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1 /**************************************************************************** |
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2 ** |
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3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). |
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4 ** All rights reserved. |
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5 ** Contact: Nokia Corporation (qt-info@nokia.com) |
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6 ** |
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7 ** This file is part of the Qt3Support module of the Qt Toolkit. |
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8 ** |
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9 ** $QT_BEGIN_LICENSE:LGPL$ |
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10 ** No Commercial Usage |
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11 ** This file contains pre-release code and may not be distributed. |
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12 ** You may use this file in accordance with the terms and conditions |
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13 ** contained in the Technology Preview License Agreement accompanying |
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14 ** this package. |
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15 ** |
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16 ** GNU Lesser General Public License Usage |
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17 ** Alternatively, this file may be used under the terms of the GNU Lesser |
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18 ** General Public License version 2.1 as published by the Free Software |
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19 ** Foundation and appearing in the file LICENSE.LGPL included in the |
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20 ** packaging of this file. Please review the following information to |
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21 ** ensure the GNU Lesser General Public License version 2.1 requirements |
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22 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. |
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23 ** |
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24 ** In addition, as a special exception, Nokia gives you certain additional |
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25 ** rights. These rights are described in the Nokia Qt LGPL Exception |
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26 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. |
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27 ** |
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28 ** If you have questions regarding the use of this file, please contact |
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29 ** Nokia at qt-info@nokia.com. |
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30 ** |
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31 ** |
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32 ** |
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33 ** |
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34 ** |
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35 ** |
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36 ** |
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37 ** |
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38 ** $QT_END_LICENSE$ |
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39 ** |
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40 ****************************************************************************/ |
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41 |
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42 #include <qplatformdefs.h> |
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43 #include "q3sqlcursor.h" |
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44 |
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45 #ifndef QT_NO_SQL |
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46 |
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47 #include "qsqldriver.h" |
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48 #include "qsqlresult.h" |
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49 #include "qdatetime.h" |
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50 #include "qsqldatabase.h" |
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51 #include "qsql.h" |
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52 #include "q3sqlrecordinfo.h" |
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53 #include "q3sqlfieldinfo.h" |
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54 |
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55 QT_BEGIN_NAMESPACE |
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56 |
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57 class Q3SqlCursorPrivate |
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58 { |
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59 public: |
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60 |
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61 Q3SqlCursorPrivate(const QString& name, QSqlDatabase sdb) |
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62 : lastAt(QSql::BeforeFirst), nm(name), srt(name), md(0), db(sdb), q(0) |
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63 {} |
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64 ~Q3SqlCursorPrivate() |
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65 { |
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66 delete q; |
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67 } |
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68 |
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69 QSqlQuery* query() |
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70 { |
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71 if (!q) |
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72 q = new QSqlQuery(QString(), db); |
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73 return q; |
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74 } |
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75 |
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76 int lastAt; |
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77 QString nm; //name |
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78 QSqlIndex srt; //sort |
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79 QString ftr; //filter |
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80 int md; //mode |
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81 QSqlIndex priIndx; //primary index |
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82 QSqlRecord editBuffer; |
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83 // the primary index as it was before the user changed the values in editBuffer |
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84 QString editIndex; |
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85 Q3SqlRecordInfo infoBuffer; |
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86 QSqlDatabase db; |
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87 QSqlQuery *q; |
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88 }; |
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89 |
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90 QString qOrderByClause(const QSqlIndex & i, const QString& prefix = QString()) |
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91 { |
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92 QString str; |
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93 int k = i.count(); |
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94 if(k == 0) |
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95 return QString(); |
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96 str = QLatin1String(" order by ") + i.toString(prefix); |
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97 return str; |
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98 } |
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99 |
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100 QString qWhereClause(const QString& prefix, QSqlField* field, const QSqlDriver* driver) |
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101 { |
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102 QString f; |
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103 if (field && driver) { |
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104 if (!prefix.isEmpty()) |
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105 f += prefix + QLatin1Char('.'); |
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106 f += field->name(); |
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107 if (field->isNull()) { |
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108 f += QLatin1String(" IS NULL"); |
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109 } else { |
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110 f += QLatin1String(" = ") + driver->formatValue(field); |
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111 } |
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112 } |
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113 return f; |
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114 } |
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115 |
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116 QString qWhereClause(QSqlRecord* rec, const QString& prefix, const QString& sep, |
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117 const QSqlDriver* driver) |
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118 { |
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119 static QString blank(QLatin1Char(' ')); |
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120 QString filter; |
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121 bool separator = false; |
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122 for (int j = 0; j < rec->count(); ++j) { |
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123 QSqlField f = rec->field(j); |
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124 if (rec->isGenerated(j)) { |
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125 if (separator) |
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126 filter += sep + blank; |
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127 filter += qWhereClause(prefix, &f, driver); |
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128 filter += blank; |
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129 separator = true; |
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130 } |
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131 } |
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132 return filter; |
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133 } |
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134 |
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135 /*! |
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136 \class Q3SqlCursor |
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137 \brief The Q3SqlCursor class provides browsing and editing of SQL |
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138 tables and views. |
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139 |
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140 \compat |
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141 |
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142 A Q3SqlCursor is a database record (see \l QSqlRecord) that |
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143 corresponds to a table or view within an SQL database (see \l |
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144 QSqlDatabase). There are two buffers in a cursor, one used for |
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145 browsing and one used for editing records. Each buffer contains a |
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146 list of fields which correspond to the fields in the table or |
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147 view. |
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148 |
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149 When positioned on a valid record, the browse buffer contains the |
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150 values of the current record's fields from the database. The edit |
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151 buffer is separate, and is used for editing existing records and |
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152 inserting new records. |
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153 |
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154 For browsing data, a cursor must first select() data from the |
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155 database. After a successful select() the cursor is active |
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156 (isActive() returns true), but is initially not positioned on a |
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157 valid record (isValid() returns false). To position the cursor on |
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158 a valid record, use one of the navigation functions, next(), |
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159 previous(), first(), last(), or seek(). Once positioned on a valid |
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160 record, data can be retrieved from the browse buffer using |
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161 value(). If a navigation function is not successful, it returns |
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162 false, the cursor will no longer be positioned on a valid record |
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163 and the values returned by value() are undefined. |
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164 |
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165 For example: |
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166 |
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167 \snippet doc/src/snippets/code/src_qt3support_sql_q3sqlcursor.cpp 0 |
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168 |
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169 In the above example, a cursor is created specifying a table or |
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170 view name in the database. Then, select() is called, which can be |
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171 optionally parameterised to filter and order the records |
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172 retrieved. Each record in the cursor is retrieved using next(). |
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173 When next() returns false, there are no more records to process, |
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174 and the loop terminates. |
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175 |
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176 For editing records (rows of data), a cursor contains a separate |
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177 edit buffer which is independent of the fields used when browsing. |
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178 The functions insert(), update() and del() operate on the edit |
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179 buffer. This allows the cursor to be repositioned to other |
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180 records while simultaneously maintaining a separate buffer for |
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181 edits. You can get a pointer to the edit buffer using |
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182 editBuffer(). The primeInsert(), primeUpdate() and primeDelete() |
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183 functions also return a pointer to the edit buffer and prepare it |
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184 for insert, update and delete respectively. Edit operations only |
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185 affect a single row at a time. Note that update() and del() |
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186 require that the table or view contain a primaryIndex() to ensure |
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187 that edit operations affect a unique record within the database. |
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188 |
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189 For example: |
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190 |
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191 \snippet doc/src/snippets/code/src_qt3support_sql_q3sqlcursor.cpp 1 |
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192 |
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193 To edit an existing database record, first move to the record you |
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194 wish to update. Call primeUpdate() to get the pointer to the |
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195 cursor's edit buffer. Then use this pointer to modify the values |
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196 in the edit buffer. Finally, call update() to save the changes to |
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197 the database. The values in the edit buffer will be used to |
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198 locate the appropriate record when updating the database (see |
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199 primaryIndex()). |
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200 |
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201 Similarly, when deleting an existing database record, first move |
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202 to the record you wish to delete. Then, call primeDelete() to get |
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203 the pointer to the edit buffer. Finally, call del() to delete the |
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204 record from the database. Again, the values in the edit buffer |
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205 will be used to locate and delete the appropriate record. |
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206 |
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207 To insert a new record, call primeInsert() to get the pointer to |
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208 the edit buffer. Use this pointer to populate the edit buffer |
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209 with new values and then insert() the record into the database. |
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210 |
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211 After calling insert(), update() or del(), the cursor is no longer |
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212 positioned on a valid record and can no longer be navigated |
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213 (isValid() return false). The reason for this is that any changes |
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214 made to the database will not be visible until select() is called |
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215 to refresh the cursor. You can change this behavior by passing |
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216 false to insert(), update() or del() which will prevent the cursor |
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217 from becoming invalid. The edits will still not be visible when |
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218 navigating the cursor until select() is called. |
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219 |
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220 Q3SqlCursor contains virtual methods which allow editing behavior |
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221 to be customized by subclasses. This allows custom cursors to be |
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222 created that encapsulate the editing behavior of a database table |
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223 for an entire application. For example, a cursor can be customized |
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224 to always auto-number primary index fields, or provide fields with |
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225 suitable default values, when inserting new records. Q3SqlCursor |
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226 generates SQL statements which are sent to the database engine; |
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227 you can control which fields are included in these statements |
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228 using setGenerated(). |
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229 |
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230 Note that Q3SqlCursor does not inherit from QObject. This means |
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231 that you are responsible for destroying instances of this class |
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232 yourself. However if you create a Q3SqlCursor and use it in a |
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233 \l Q3DataTable, \l Q3DataBrowser or a \l Q3DataView these classes will |
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234 usually take ownership of the cursor and destroy it when they |
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235 don't need it anymore. The documentation for Q3DataTable, |
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236 Q3DataBrowser and Q3DataView explicitly states which calls take |
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237 ownership of the cursor. |
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238 */ |
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239 |
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240 /*! |
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241 \enum Q3SqlCursor::Mode |
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242 |
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243 This enum type describes how Q3SqlCursor operates on records in the |
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244 database. |
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245 |
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246 \value ReadOnly the cursor can only SELECT records from the |
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247 database. |
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248 |
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249 \value Insert the cursor can INSERT records into the database. |
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250 |
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251 \value Update the cursor can UPDATE records in the database. |
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252 |
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253 \value Delete the cursor can DELETE records from the database. |
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254 |
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255 \value Writable the cursor can INSERT, UPDATE and DELETE records |
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256 in the database. |
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257 */ |
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258 |
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259 /*! |
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260 \fn QVariant Q3SqlCursor::value(const QString &name) const |
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261 |
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262 \overload |
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263 |
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264 Returns the value of the field named \a name. |
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265 */ |
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266 |
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267 /*! |
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268 \fn void Q3SqlCursor::setValue(const QString &name, const QVariant &val) |
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269 |
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270 \overload |
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271 |
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272 Sets the value for the field named \a name to \a val. |
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273 */ |
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274 |
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275 /*! |
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276 Constructs a cursor on database \a db using table or view \a name. |
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277 |
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278 If \a autopopulate is true (the default), the \a name of the |
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279 cursor must correspond to an existing table or view name in the |
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280 database so that field information can be automatically created. |
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281 If the table or view does not exist, the cursor will not be |
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282 functional. |
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283 |
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284 The cursor is created with an initial mode of Q3SqlCursor::Writable |
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285 (meaning that records can be inserted, updated or deleted using |
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286 the cursor). If the cursor does not have a unique primary index, |
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287 update and deletes cannot be performed. |
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288 |
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289 Note that \a autopopulate refers to populating the cursor with |
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290 meta-data, e.g. the names of the table's fields, not with |
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291 retrieving data. The select() function is used to populate the |
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292 cursor with data. |
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293 |
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294 \sa setName() setMode() |
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295 */ |
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296 |
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297 Q3SqlCursor::Q3SqlCursor(const QString & name, bool autopopulate, QSqlDatabase db) |
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298 : QSqlRecord(), QSqlQuery(QString(), db) |
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299 { |
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300 d = new Q3SqlCursorPrivate(name, db); |
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301 setMode(Writable); |
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302 if (!d->nm.isEmpty()) |
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303 setName(d->nm, autopopulate); |
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304 } |
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305 |
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306 /*! |
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307 Constructs a copy of \a other. |
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308 */ |
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309 |
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310 Q3SqlCursor::Q3SqlCursor(const Q3SqlCursor & other) |
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311 : QSqlRecord(other), QSqlQuery(other) |
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312 { |
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313 d = new Q3SqlCursorPrivate(other.d->nm, other.d->db); |
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314 d->lastAt = other.d->lastAt; |
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315 d->nm = other.d->nm; |
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316 d->srt = other.d->srt; |
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317 d->ftr = other.d->ftr; |
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318 d->priIndx = other.d->priIndx; |
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319 d->editBuffer = other.d->editBuffer; |
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320 d->infoBuffer = other.d->infoBuffer; |
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321 d->q = 0; // do not share queries |
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322 setMode(other.mode()); |
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323 } |
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324 |
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325 /*! |
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326 Destroys the object and frees any allocated resources. |
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327 */ |
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328 |
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329 Q3SqlCursor::~Q3SqlCursor() |
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330 { |
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331 delete d; |
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332 } |
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333 |
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334 /*! |
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335 Sets the cursor equal to \a other. |
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336 */ |
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337 |
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338 Q3SqlCursor& Q3SqlCursor::operator=(const Q3SqlCursor& other) |
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339 { |
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340 QSqlRecord::operator=(other); |
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341 QSqlQuery::operator=(other); |
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342 delete d; |
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343 d = new Q3SqlCursorPrivate(other.d->nm, other.d->db); |
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344 d->lastAt = other.d->lastAt; |
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345 d->nm = other.d->nm; |
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346 d->srt = other.d->srt; |
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347 d->ftr = other.d->ftr; |
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348 d->priIndx = other.d->priIndx; |
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349 d->editBuffer = other.d->editBuffer; |
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350 d->infoBuffer = other.d->infoBuffer; |
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351 d->q = 0; // do not share queries |
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352 setMode(other.mode()); |
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353 return *this; |
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354 } |
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355 |
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356 /*! |
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357 Sets the current sort to \a sort. Note that no new records are |
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358 selected. To select new records, use select(). The \a sort will |
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359 apply to any subsequent select() calls that do not explicitly |
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360 specify a sort. |
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361 */ |
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362 |
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363 void Q3SqlCursor::setSort(const QSqlIndex& sort) |
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364 { |
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365 d->srt = sort; |
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366 } |
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367 |
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368 /*! |
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369 Returns the current sort, or an empty index if there is no current |
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370 sort. |
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371 */ |
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372 QSqlIndex Q3SqlCursor::sort() const |
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373 { |
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374 return d->srt; |
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375 } |
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376 |
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377 /*! |
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378 Sets the current filter to \a filter. Note that no new records are |
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379 selected. To select new records, use select(). The \a filter will |
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380 apply to any subsequent select() calls that do not explicitly |
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381 specify a filter. |
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382 |
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383 The filter is a SQL \c WHERE clause without the keyword 'WHERE', |
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384 e.g. \c{name='Dave'} which will be processed by the DBMS. |
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385 */ |
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386 void Q3SqlCursor::setFilter(const QString& filter) |
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387 { |
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388 d->ftr = filter; |
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389 } |
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390 |
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391 /*! |
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392 Returns the current filter, or an empty string if there is no |
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393 current filter. |
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394 */ |
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395 QString Q3SqlCursor::filter() const |
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396 { |
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397 return d->ftr; |
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398 } |
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399 |
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400 /*! |
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401 Sets the name of the cursor to \a name. If \a autopopulate is true |
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402 (the default), the \a name must correspond to a valid table or |
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403 view name in the database. Also, note that all references to the |
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404 cursor edit buffer become invalidated when fields are |
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405 auto-populated. See the Q3SqlCursor constructor documentation for |
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406 more information. |
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407 */ |
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408 void Q3SqlCursor::setName(const QString& name, bool autopopulate) |
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409 { |
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410 d->nm = name; |
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411 if (autopopulate) { |
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412 if (driver()) { |
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413 d->infoBuffer = driver()->record(name); |
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414 *this = d->infoBuffer.toRecord(); |
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415 d->editBuffer = *this; |
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416 d->priIndx = driver()->primaryIndex(name); |
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417 } |
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418 if (isEmpty()) |
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419 qWarning("Q3SqlCursor::setName: unable to build record, does '%s' exist?", name.latin1()); |
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420 } |
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421 } |
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422 |
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423 /*! |
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424 Returns the name of the cursor. |
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425 */ |
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426 |
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427 QString Q3SqlCursor::name() const |
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428 { |
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429 return d->nm; |
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430 } |
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431 |
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432 /*! \internal |
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433 */ |
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434 |
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435 QString Q3SqlCursor::toString(const QString& prefix, const QString& sep) const |
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436 { |
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437 QString pflist; |
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438 QString pfix = prefix.isEmpty() ? prefix : prefix + QLatin1Char('.'); |
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439 bool comma = false; |
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440 |
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441 for (int i = 0; i < count(); ++i) { |
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442 const QString fname = fieldName(i); |
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443 if (isGenerated(i)) { |
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444 if(comma) |
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445 pflist += sep + QLatin1Char(' '); |
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446 pflist += pfix + driver()->escapeIdentifier(fname, QSqlDriver::FieldName); |
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447 comma = true; |
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448 } |
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449 } |
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450 return pflist; |
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451 } |
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452 |
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453 /*! |
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454 \internal |
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455 |
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456 Assigns the record \a list. |
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457 |
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458 */ |
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459 QSqlRecord & Q3SqlCursor::operator=(const QSqlRecord & list) |
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460 { |
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461 return QSqlRecord::operator=(list); |
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462 } |
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463 |
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464 /*! |
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465 Append a copy of field \a fieldInfo to the end of the cursor. Note |
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466 that all references to the cursor edit buffer become invalidated. |
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467 */ |
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468 |
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469 void Q3SqlCursor::append(const Q3SqlFieldInfo& fieldInfo) |
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470 { |
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471 d->editBuffer.append(fieldInfo.toField()); |
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472 d->infoBuffer.append(fieldInfo); |
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473 QSqlRecord::append(fieldInfo.toField()); |
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474 } |
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475 |
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476 /*! |
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477 Removes all fields from the cursor. Note that all references to |
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478 the cursor edit buffer become invalidated. |
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479 */ |
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480 void Q3SqlCursor::clear() |
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481 { |
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482 d->editBuffer.clear(); |
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483 d->infoBuffer.clear(); |
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484 QSqlRecord::clear(); |
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485 } |
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486 |
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487 |
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488 /*! |
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489 Insert a copy of \a fieldInfo at position \a pos. If a field |
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490 already exists at \a pos, it is removed. Note that all references |
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491 to the cursor edit buffer become invalidated. |
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492 */ |
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493 |
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494 void Q3SqlCursor::insert(int pos, const Q3SqlFieldInfo& fieldInfo) |
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495 { |
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496 d->editBuffer.replace(pos, fieldInfo.toField()); |
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497 d->infoBuffer[pos] = fieldInfo; |
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498 QSqlRecord::replace(pos, fieldInfo.toField()); |
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499 } |
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500 |
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501 /*! |
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502 Removes the field at \a pos. If \a pos does not exist, nothing |
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503 happens. Note that all references to the cursor edit buffer become |
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504 invalidated. |
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505 */ |
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506 |
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507 void Q3SqlCursor::remove(int pos) |
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508 { |
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509 d->editBuffer.remove(pos); |
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510 d->infoBuffer[pos] = Q3SqlFieldInfo(); |
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511 QSqlRecord::remove(pos); |
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512 } |
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513 |
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514 /*! |
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515 Sets the generated flag for the field \a name to \a generated. If |
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516 the field does not exist, nothing happens. Only fields that have |
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517 \a generated set to true are included in the SQL that is |
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518 generated by insert(), update() or del(). |
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519 */ |
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520 |
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521 void Q3SqlCursor::setGenerated(const QString& name, bool generated) |
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522 { |
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523 int pos = indexOf(name); |
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524 if (pos == -1) |
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525 return; |
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526 QSqlRecord::setGenerated(name, generated); |
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527 d->editBuffer.setGenerated(name, generated); |
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528 d->infoBuffer[pos].setGenerated(generated); |
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529 } |
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530 |
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531 /*! |
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532 \overload |
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533 |
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534 Sets the generated flag for the field \a i to \a generated. |
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535 */ |
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536 void Q3SqlCursor::setGenerated(int i, bool generated) |
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537 { |
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538 if (i < 0 || i >= (int)d->infoBuffer.count()) |
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539 return; |
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540 QSqlRecord::setGenerated(i, generated); |
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541 d->editBuffer.setGenerated(i, generated); |
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542 d->infoBuffer[i].setGenerated(generated); |
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543 } |
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544 |
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545 /*! |
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546 Returns the primary index associated with the cursor as defined in |
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547 the database, or an empty index if there is no primary index. If |
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548 \a setFromCursor is true (the default), the index fields are |
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549 populated with the corresponding values in the cursor's current |
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550 record. |
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551 */ |
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552 |
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553 QSqlIndex Q3SqlCursor::primaryIndex(bool setFromCursor) const |
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554 { |
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555 if (setFromCursor) { |
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556 for (int i = 0; i < d->priIndx.count(); ++i) { |
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557 const QString fn = d->priIndx.fieldName(i); |
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558 if (contains(fn)) |
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559 d->priIndx.setValue(i, QSqlRecord::value(fn)); |
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560 } |
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561 } |
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562 return d->priIndx; |
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563 } |
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564 |
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565 /*! |
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566 Sets the primary index associated with the cursor to the index \a |
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567 idx. Note that this index must contain a field or set of fields |
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568 which identify a unique record within the underlying database |
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569 table or view so that update() and del() will execute as expected. |
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570 |
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571 \sa update() del() |
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572 */ |
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573 |
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574 void Q3SqlCursor::setPrimaryIndex(const QSqlIndex& idx) |
|
575 { |
|
576 d->priIndx = idx; |
|
577 } |
|
578 |
|
579 |
|
580 /*! |
|
581 Returns an index composed of \a fieldNames, all in ASCending |
|
582 order. Note that all field names must exist in the cursor, |
|
583 otherwise an empty index is returned. |
|
584 |
|
585 \sa QSqlIndex |
|
586 */ |
|
587 |
|
588 QSqlIndex Q3SqlCursor::index(const QStringList& fieldNames) const |
|
589 { |
|
590 QSqlIndex idx; |
|
591 for (QStringList::ConstIterator it = fieldNames.begin(); it != fieldNames.end(); ++it) { |
|
592 QSqlField f = field((*it)); |
|
593 if (!f.isValid()) { /* all fields must exist */ |
|
594 idx.clear(); |
|
595 break; |
|
596 } |
|
597 idx.append(f); |
|
598 } |
|
599 return idx; |
|
600 } |
|
601 |
|
602 /*! |
|
603 \overload |
|
604 |
|
605 Returns an index based on \a fieldName. |
|
606 */ |
|
607 |
|
608 QSqlIndex Q3SqlCursor::index(const QString& fieldName) const |
|
609 { |
|
610 QStringList fl(fieldName); |
|
611 return index(fl); |
|
612 } |
|
613 |
|
614 /*! |
|
615 Selects all fields in the cursor from the database matching the |
|
616 filter criteria \a filter. The data is returned in the order |
|
617 specified by the index \a sort. Returns true if the data was |
|
618 successfully selected; otherwise returns false. |
|
619 |
|
620 The \a filter is a string containing a SQL \c WHERE clause but |
|
621 without the 'WHERE' keyword. The cursor is initially positioned at |
|
622 an invalid row after this function is called. To move to a valid |
|
623 row, use seek(), first(), last(), previous() or next(). |
|
624 |
|
625 Example: |
|
626 \snippet doc/src/snippets/code/src_qt3support_sql_q3sqlcursor.cpp 2 |
|
627 |
|
628 The filter will apply to any subsequent select() calls that do not |
|
629 explicitly specify another filter. Similarly the sort will apply |
|
630 to any subsequent select() calls that do not explicitly specify |
|
631 another sort. |
|
632 |
|
633 \snippet doc/src/snippets/code/src_qt3support_sql_q3sqlcursor.cpp 3 |
|
634 |
|
635 */ |
|
636 |
|
637 bool Q3SqlCursor::select(const QString & filter, const QSqlIndex & sort) |
|
638 { |
|
639 QString fieldList(toString(d->nm)); |
|
640 if (fieldList.isEmpty()) |
|
641 return false; |
|
642 QString str(QLatin1String("select ") + fieldList); |
|
643 str += QLatin1String(" from ") + d->nm; |
|
644 if (!filter.isEmpty()) { |
|
645 d->ftr = filter; |
|
646 str += QLatin1String(" where ") + filter; |
|
647 } else |
|
648 d->ftr.clear(); |
|
649 if (sort.count() > 0) |
|
650 str += QLatin1String(" order by ") + sort.toString(d->nm); |
|
651 d->srt = sort; |
|
652 return exec(str); |
|
653 } |
|
654 |
|
655 /*! |
|
656 \overload |
|
657 |
|
658 Selects all fields in the cursor from the database. The rows are |
|
659 returned in the order specified by the last call to setSort() or |
|
660 the last call to select() that specified a sort, whichever is the |
|
661 most recent. If there is no current sort, the order in which the |
|
662 rows are returned is undefined. The records are filtered according |
|
663 to the filter specified by the last call to setFilter() or the |
|
664 last call to select() that specified a filter, whichever is the |
|
665 most recent. If there is no current filter, all records are |
|
666 returned. The cursor is initially positioned at an invalid row. To |
|
667 move to a valid row, use seek(), first(), last(), previous() or |
|
668 next(). |
|
669 |
|
670 \sa setSort() setFilter() |
|
671 */ |
|
672 |
|
673 bool Q3SqlCursor::select() |
|
674 { |
|
675 return select(filter(), sort()); |
|
676 } |
|
677 |
|
678 /*! |
|
679 \overload |
|
680 |
|
681 Selects all fields in the cursor from the database. The data is |
|
682 returned in the order specified by the index \a sort. The records |
|
683 are filtered according to the filter specified by the last call to |
|
684 setFilter() or the last call to select() that specified a filter, |
|
685 whichever is the most recent. The cursor is initially positioned |
|
686 at an invalid row. To move to a valid row, use seek(), first(), |
|
687 last(), previous() or next(). |
|
688 */ |
|
689 |
|
690 bool Q3SqlCursor::select(const QSqlIndex& sort) |
|
691 { |
|
692 return select(filter(), sort); |
|
693 } |
|
694 |
|
695 /*! |
|
696 \overload |
|
697 |
|
698 Selects all fields in the cursor matching the filter index \a |
|
699 filter. The data is returned in the order specified by the index |
|
700 \a sort. The \a filter index works by constructing a WHERE clause |
|
701 using the names of the fields from the \a filter and their values |
|
702 from the current cursor record. The cursor is initially positioned |
|
703 at an invalid row. To move to a valid row, use seek(), first(), |
|
704 last(), previous() or next(). This function is useful, for example, |
|
705 for retrieving data based upon a table's primary index: |
|
706 |
|
707 \snippet doc/src/snippets/code/src_qt3support_sql_q3sqlcursor.cpp 4 |
|
708 |
|
709 In this example the QSqlIndex, pk, is used for two different |
|
710 purposes. When used as the filter (first) argument, the field |
|
711 names it contains are used to construct the WHERE clause, each set |
|
712 to the current cursor value, \c{WHERE id=10}, in this case. When |
|
713 used as the sort (second) argument the field names it contains are |
|
714 used for the ORDER BY clause, \c{ORDER BY id} in this example. |
|
715 */ |
|
716 |
|
717 bool Q3SqlCursor::select(const QSqlIndex & filter, const QSqlIndex & sort) |
|
718 { |
|
719 return select(toString(filter, this, d->nm, QString(QLatin1Char('=')), QLatin1String("and")), sort); |
|
720 } |
|
721 |
|
722 /*! |
|
723 Sets the cursor mode to \a mode. This value can be an OR'ed |
|
724 combination of \l Q3SqlCursor::Mode values. The default mode for a |
|
725 cursor is Q3SqlCursor::Writable. |
|
726 |
|
727 \snippet doc/src/snippets/code/src_qt3support_sql_q3sqlcursor.cpp 5 |
|
728 */ |
|
729 |
|
730 void Q3SqlCursor::setMode(int mode) |
|
731 { |
|
732 d->md = mode; |
|
733 } |
|
734 |
|
735 /*! |
|
736 Returns the current cursor mode. |
|
737 |
|
738 \sa setMode() |
|
739 */ |
|
740 |
|
741 int Q3SqlCursor::mode() const |
|
742 { |
|
743 return d->md; |
|
744 } |
|
745 |
|
746 /*! |
|
747 Sets field \a name to \a calculated. If the field \a name does not |
|
748 exist, nothing happens. The value of a calculated field is set by |
|
749 the calculateField() virtual function which you must reimplement |
|
750 (or the field value will be an invalid QVariant). Calculated |
|
751 fields do not appear in generated SQL statements sent to the |
|
752 database. |
|
753 |
|
754 \sa calculateField() |
|
755 */ |
|
756 |
|
757 void Q3SqlCursor::setCalculated(const QString& name, bool calculated) |
|
758 { |
|
759 int pos = indexOf(name); |
|
760 if (pos < 0) |
|
761 return; |
|
762 d->infoBuffer[pos].setCalculated(calculated); |
|
763 if (calculated) |
|
764 setGenerated(pos, false); |
|
765 } |
|
766 |
|
767 /*! |
|
768 Returns true if the field \a name exists and is calculated; |
|
769 otherwise returns false. |
|
770 |
|
771 \sa setCalculated() |
|
772 */ |
|
773 |
|
774 bool Q3SqlCursor::isCalculated(const QString& name) const |
|
775 { |
|
776 int pos = indexOf(name); |
|
777 if (pos < 0) |
|
778 return false; |
|
779 return d->infoBuffer[pos].isCalculated(); |
|
780 } |
|
781 |
|
782 /*! |
|
783 Sets field \a{name}'s trimmed status to \a trim. If the field \a |
|
784 name does not exist, nothing happens. |
|
785 |
|
786 When a trimmed field of type string is read from the |
|
787 database any trailing (right-most) spaces are removed. |
|
788 |
|
789 \sa isTrimmed() QVariant |
|
790 */ |
|
791 |
|
792 void Q3SqlCursor::setTrimmed(const QString& name, bool trim) |
|
793 { |
|
794 int pos = indexOf(name); |
|
795 if (pos < 0) |
|
796 return; |
|
797 d->infoBuffer[pos].setTrim(trim); |
|
798 } |
|
799 |
|
800 /*! |
|
801 Returns true if the field \a name exists and is trimmed; otherwise |
|
802 returns false. |
|
803 |
|
804 When a trimmed field of type string or cstring is read from the |
|
805 database any trailing (right-most) spaces are removed. |
|
806 |
|
807 \sa setTrimmed() |
|
808 */ |
|
809 |
|
810 bool Q3SqlCursor::isTrimmed(const QString& name) const |
|
811 { |
|
812 int pos = indexOf(name); |
|
813 if (pos < 0) |
|
814 return false; |
|
815 return d->infoBuffer[pos].isTrim(); |
|
816 } |
|
817 |
|
818 /*! |
|
819 Returns true if the cursor is read-only; otherwise returns false. |
|
820 The default is false. Read-only cursors cannot be edited using |
|
821 insert(), update() or del(). |
|
822 |
|
823 \sa setMode() |
|
824 */ |
|
825 |
|
826 bool Q3SqlCursor::isReadOnly() const |
|
827 { |
|
828 return d->md == 0; |
|
829 } |
|
830 |
|
831 /*! |
|
832 Returns true if the cursor will perform inserts; otherwise returns |
|
833 false. |
|
834 |
|
835 \sa setMode() |
|
836 */ |
|
837 |
|
838 bool Q3SqlCursor::canInsert() const |
|
839 { |
|
840 return ((d->md & Insert) == Insert) ; |
|
841 } |
|
842 |
|
843 |
|
844 /*! |
|
845 Returns true if the cursor will perform updates; otherwise returns |
|
846 false. |
|
847 |
|
848 \sa setMode() |
|
849 */ |
|
850 |
|
851 bool Q3SqlCursor::canUpdate() const |
|
852 { |
|
853 return ((d->md & Update) == Update) ; |
|
854 } |
|
855 |
|
856 /*! |
|
857 Returns true if the cursor will perform deletes; otherwise returns |
|
858 false. |
|
859 |
|
860 \sa setMode() |
|
861 */ |
|
862 |
|
863 bool Q3SqlCursor::canDelete() const |
|
864 { |
|
865 return ((d->md & Delete) == Delete) ; |
|
866 } |
|
867 |
|
868 /*! |
|
869 \overload |
|
870 |
|
871 Returns a formatted string composed of the \a prefix (e.g. table |
|
872 or view name), ".", the \a field name, the \a fieldSep and the |
|
873 field value. If the \a prefix is empty then the string will begin |
|
874 with the \a field name. This function is useful for generating SQL |
|
875 statements. |
|
876 */ |
|
877 |
|
878 QString Q3SqlCursor::toString(const QString& prefix, QSqlField* field, const QString& fieldSep) const |
|
879 { |
|
880 QString f; |
|
881 if (field && driver()) { |
|
882 f = (prefix.length() > 0 ? prefix + QLatin1Char('.') : QString()) + driver()->escapeIdentifier(field->name(), QSqlDriver::FieldName); |
|
883 f += QLatin1Char(' ') + fieldSep + QLatin1Char(' '); |
|
884 if (field->isNull()) { |
|
885 f += QLatin1String("NULL"); |
|
886 } else { |
|
887 f += driver()->formatValue(field); |
|
888 } |
|
889 } |
|
890 return f; |
|
891 } |
|
892 |
|
893 /*! |
|
894 Returns a formatted string composed of all the fields in \a rec. |
|
895 Each field is composed of the \a prefix (e.g. table or view name), |
|
896 ".", the field name, the \a fieldSep and the field value. If the |
|
897 \a prefix is empty then each field will begin with the field name. |
|
898 The fields are then joined together separated by \a sep. Fields |
|
899 where isGenerated() returns false are not included. This function |
|
900 is useful for generating SQL statements. |
|
901 */ |
|
902 |
|
903 QString Q3SqlCursor::toString(QSqlRecord* rec, const QString& prefix, const QString& fieldSep, |
|
904 const QString& sep) const |
|
905 { |
|
906 static QString blank(QLatin1Char(' ')); |
|
907 QString filter; |
|
908 bool separator = false; |
|
909 for (int j = 0; j < count(); ++j) { |
|
910 QSqlField f = rec->field(j); |
|
911 if (rec->isGenerated(j)) { |
|
912 if (separator) |
|
913 filter += sep + blank; |
|
914 filter += toString(prefix, &f, fieldSep); |
|
915 filter += blank; |
|
916 separator = true; |
|
917 } |
|
918 } |
|
919 return filter; |
|
920 } |
|
921 |
|
922 /*! |
|
923 \overload |
|
924 |
|
925 Returns a formatted string composed of all the fields in the index |
|
926 \a i. Each field is composed of the \a prefix (e.g. table or view |
|
927 name), ".", the field name, the \a fieldSep and the field value. |
|
928 If the \a prefix is empty then each field will begin with the field |
|
929 name. The field values are taken from \a rec. The fields are then |
|
930 joined together separated by \a sep. Fields where isGenerated() |
|
931 returns false are ignored. This function is useful for generating |
|
932 SQL statements. |
|
933 */ |
|
934 |
|
935 QString Q3SqlCursor::toString(const QSqlIndex& i, QSqlRecord* rec, const QString& prefix, |
|
936 const QString& fieldSep, const QString& sep) const |
|
937 { |
|
938 QString filter; |
|
939 bool separator = false; |
|
940 for(int j = 0; j < i.count(); ++j){ |
|
941 if (rec->isGenerated(j)) { |
|
942 if(separator) { |
|
943 filter += QLatin1Char(' ') + sep + QLatin1Char(' ') ; |
|
944 } |
|
945 QString fn = i.fieldName(j); |
|
946 QSqlField f = rec->field(fn); |
|
947 filter += toString(prefix, &f, fieldSep); |
|
948 separator = true; |
|
949 } |
|
950 } |
|
951 return filter; |
|
952 } |
|
953 |
|
954 /*! |
|
955 Inserts the current contents of the cursor's edit record buffer |
|
956 into the database, if the cursor allows inserts. Returns the |
|
957 number of rows affected by the insert. For error information, use |
|
958 lastError(). |
|
959 |
|
960 If \a invalidate is true (the default), the cursor will no longer |
|
961 be positioned on a valid record and can no longer be navigated. A |
|
962 new select() call must be made before navigating to a valid |
|
963 record. |
|
964 |
|
965 \snippet doc/src/snippets/code/src_qt3support_sql_q3sqlcursor.cpp 6 |
|
966 |
|
967 In the above example, a cursor is created on the 'prices' table |
|
968 and a pointer to the insert buffer is acquired using primeInsert(). |
|
969 Each field's value is set to the desired value and then insert() |
|
970 is called to insert the data into the database. Remember: all edit |
|
971 operations (insert(), update() and delete()) operate on the |
|
972 contents of the cursor edit buffer and not on the contents of the |
|
973 cursor itself. |
|
974 |
|
975 \sa setMode() lastError() |
|
976 */ |
|
977 |
|
978 int Q3SqlCursor::insert(bool invalidate) |
|
979 { |
|
980 if ((d->md & Insert) != Insert || !driver()) |
|
981 return false; |
|
982 int k = d->editBuffer.count(); |
|
983 if (k == 0) |
|
984 return 0; |
|
985 |
|
986 QString fList; |
|
987 QString vList; |
|
988 bool comma = false; |
|
989 // use a prepared query if the driver supports it |
|
990 if (driver()->hasFeature(QSqlDriver::PreparedQueries)) { |
|
991 int cnt = 0; |
|
992 bool oraStyle = driver()->hasFeature(QSqlDriver::NamedPlaceholders); |
|
993 for(int j = 0; j < k; ++j) { |
|
994 QSqlField f = d->editBuffer.field(j); |
|
995 if (d->editBuffer.isGenerated(j)) { |
|
996 if (comma) { |
|
997 fList += QLatin1Char(','); |
|
998 vList += QLatin1Char(','); |
|
999 } |
|
1000 fList += driver()->escapeIdentifier(f.name(), QSqlDriver::FieldName); |
|
1001 vList += (oraStyle == true) ? QLatin1String(":f") + QString::number(cnt) : QString(QLatin1Char('?')); |
|
1002 cnt++; |
|
1003 comma = true; |
|
1004 } |
|
1005 } |
|
1006 if (!comma) { |
|
1007 return 0; |
|
1008 } |
|
1009 QString str; |
|
1010 str.append(QLatin1String("insert into ")).append(name()) |
|
1011 .append(QLatin1String(" (")).append(fList) |
|
1012 .append(QLatin1String(") values (")).append(vList). append(QLatin1Char(')')); |
|
1013 |
|
1014 return applyPrepared(str, invalidate); |
|
1015 } else { |
|
1016 for(int j = 0; j < k; ++j) { |
|
1017 QSqlField f = d->editBuffer.field(j); |
|
1018 if (d->editBuffer.isGenerated(j)) { |
|
1019 if (comma) { |
|
1020 fList += QLatin1Char(','); |
|
1021 vList += QLatin1Char(','); |
|
1022 } |
|
1023 fList += driver()->escapeIdentifier(f.name(), QSqlDriver::FieldName); |
|
1024 vList += driver()->formatValue(&f); |
|
1025 comma = true; |
|
1026 } |
|
1027 } |
|
1028 |
|
1029 if (!comma) { |
|
1030 // no valid fields found |
|
1031 return 0; |
|
1032 } |
|
1033 QString str; |
|
1034 str.append(QLatin1String("insert into ")).append(name()).append(QLatin1String(" (")) |
|
1035 .append(fList).append(QLatin1String(") values (")).append(vList). append (QLatin1String(")")); |
|
1036 return apply(str, invalidate); |
|
1037 } |
|
1038 } |
|
1039 |
|
1040 /*! |
|
1041 Returns the current internal edit buffer. If \a copy is true (the |
|
1042 default is false), the current cursor field values are first |
|
1043 copied into the edit buffer. The edit buffer is valid as long as |
|
1044 the cursor remains valid. The cursor retains ownership of the |
|
1045 returned pointer, so it must not be deleted or modified. |
|
1046 |
|
1047 \sa primeInsert(), primeUpdate() primeDelete() |
|
1048 */ |
|
1049 |
|
1050 QSqlRecord* Q3SqlCursor::editBuffer(bool copy) |
|
1051 { |
|
1052 sync(); |
|
1053 if (copy) { |
|
1054 for(int i = 0; i < d->editBuffer.count(); i++) { |
|
1055 if (QSqlRecord::isNull(i)) { |
|
1056 d->editBuffer.setNull(i); |
|
1057 } else { |
|
1058 d->editBuffer.setValue(i, value(i)); |
|
1059 } |
|
1060 } |
|
1061 } |
|
1062 return &d->editBuffer; |
|
1063 } |
|
1064 |
|
1065 /*! |
|
1066 This function primes the edit buffer's field values for update and |
|
1067 returns the edit buffer. The default implementation copies the |
|
1068 field values from the current cursor record into the edit buffer |
|
1069 (therefore, this function is equivalent to calling editBuffer( |
|
1070 true)). The cursor retains ownership of the returned pointer, so |
|
1071 it must not be deleted or modified. |
|
1072 |
|
1073 \sa editBuffer() update() |
|
1074 */ |
|
1075 |
|
1076 QSqlRecord* Q3SqlCursor::primeUpdate() |
|
1077 { |
|
1078 // memorize the primary keys as they were before the user changed the values in editBuffer |
|
1079 QSqlRecord* buf = editBuffer(true); |
|
1080 QSqlIndex idx = primaryIndex(false); |
|
1081 if (!idx.isEmpty()) |
|
1082 d->editIndex = toString(idx, buf, d->nm, QString(QLatin1Char('=')), QLatin1String("and")); |
|
1083 else |
|
1084 d->editIndex = qWhereClause(buf, d->nm, QLatin1String("and"), driver()); |
|
1085 return buf; |
|
1086 } |
|
1087 |
|
1088 /*! |
|
1089 This function primes the edit buffer's field values for delete and |
|
1090 returns the edit buffer. The default implementation copies the |
|
1091 field values from the current cursor record into the edit buffer |
|
1092 (therefore, this function is equivalent to calling editBuffer( |
|
1093 true)). The cursor retains ownership of the returned pointer, so |
|
1094 it must not be deleted or modified. |
|
1095 |
|
1096 \sa editBuffer() del() |
|
1097 */ |
|
1098 |
|
1099 QSqlRecord* Q3SqlCursor::primeDelete() |
|
1100 { |
|
1101 return editBuffer(true); |
|
1102 } |
|
1103 |
|
1104 /*! |
|
1105 This function primes the edit buffer's field values for insert and |
|
1106 returns the edit buffer. The default implementation clears all |
|
1107 field values in the edit buffer. The cursor retains ownership of |
|
1108 the returned pointer, so it must not be deleted or modified. |
|
1109 |
|
1110 \sa editBuffer() insert() |
|
1111 */ |
|
1112 |
|
1113 QSqlRecord* Q3SqlCursor::primeInsert() |
|
1114 { |
|
1115 d->editBuffer.clearValues(); |
|
1116 return &d->editBuffer; |
|
1117 } |
|
1118 |
|
1119 |
|
1120 /*! |
|
1121 Updates the database with the current contents of the edit buffer. |
|
1122 Returns the number of records which were updated. |
|
1123 For error information, use lastError(). |
|
1124 |
|
1125 Only records which meet the filter criteria specified by the |
|
1126 cursor's primary index are updated. If the cursor does not contain |
|
1127 a primary index, no update is performed and 0 is returned. |
|
1128 |
|
1129 If \a invalidate is true (the default), the current cursor can no |
|
1130 longer be navigated. A new select() call must be made before you |
|
1131 can move to a valid record. For example: |
|
1132 |
|
1133 \snippet doc/src/snippets/code/src_qt3support_sql_q3sqlcursor.cpp 7 |
|
1134 |
|
1135 In the above example, a cursor is created on the 'prices' table |
|
1136 and is positioned on the record to be updated. Then a pointer to |
|
1137 the cursor's edit buffer is acquired using primeUpdate(). A new |
|
1138 value is calculated and placed into the edit buffer with the |
|
1139 setValue() call. Finally, an update() call is made on the cursor |
|
1140 which uses the tables's primary index to update the record in the |
|
1141 database with the contents of the cursor's edit buffer. Remember: |
|
1142 all edit operations (insert(), update() and delete()) operate on |
|
1143 the contents of the cursor edit buffer and not on the contents of |
|
1144 the cursor itself. |
|
1145 |
|
1146 Note that if the primary index does not uniquely distinguish |
|
1147 records the database may be changed into an inconsistent state. |
|
1148 |
|
1149 \sa setMode() lastError() |
|
1150 */ |
|
1151 |
|
1152 int Q3SqlCursor::update(bool invalidate) |
|
1153 { |
|
1154 if (d->editIndex.isEmpty()) |
|
1155 return 0; |
|
1156 return update(d->editIndex, invalidate); |
|
1157 } |
|
1158 |
|
1159 /*! |
|
1160 \overload |
|
1161 |
|
1162 Updates the database with the current contents of the cursor edit |
|
1163 buffer using the specified \a filter. Returns the number of |
|
1164 records which were updated. |
|
1165 For error information, use lastError(). |
|
1166 |
|
1167 Only records which meet the filter criteria are updated, otherwise |
|
1168 all records in the table are updated. |
|
1169 |
|
1170 If \a invalidate is true (the default), the cursor can no longer |
|
1171 be navigated. A new select() call must be made before you can move |
|
1172 to a valid record. |
|
1173 |
|
1174 \sa primeUpdate() setMode() lastError() |
|
1175 */ |
|
1176 |
|
1177 int Q3SqlCursor::update(const QString & filter, bool invalidate) |
|
1178 { |
|
1179 if ((d->md & Update) != Update) { |
|
1180 return false; |
|
1181 } |
|
1182 int k = count(); |
|
1183 if (k == 0) { |
|
1184 return 0; |
|
1185 } |
|
1186 |
|
1187 // use a prepared query if the driver supports it |
|
1188 if (driver()->hasFeature(QSqlDriver::PreparedQueries)) { |
|
1189 QString fList; |
|
1190 bool comma = false; |
|
1191 int cnt = 0; |
|
1192 bool oraStyle = driver()->hasFeature(QSqlDriver::NamedPlaceholders); |
|
1193 for(int j = 0; j < k; ++j) { |
|
1194 QSqlField f = d->editBuffer.field(j); |
|
1195 if (d->editBuffer.isGenerated(j)) { |
|
1196 if (comma) { |
|
1197 fList += QLatin1Char(','); |
|
1198 } |
|
1199 fList += f.name() + QLatin1String(" = ") + (oraStyle == true ? QLatin1String(":f") + QString::number(cnt) : QString(QLatin1Char('?'))); |
|
1200 cnt++; |
|
1201 comma = true; |
|
1202 } |
|
1203 } |
|
1204 if (!comma) { |
|
1205 return 0; |
|
1206 } |
|
1207 QString str(QLatin1String("update ") + name() + QLatin1String(" set ") + fList); |
|
1208 if (filter.length()) { |
|
1209 str+= QLatin1String(" where ") + filter; |
|
1210 } |
|
1211 return applyPrepared(str, invalidate); |
|
1212 } else { |
|
1213 QString str = QLatin1String("update ") + name(); |
|
1214 str += QLatin1String(" set ") + toString(&d->editBuffer, QString(), QString(QLatin1Char('=')), QString(QLatin1Char(','))); |
|
1215 if (filter.length()) { |
|
1216 str+= QLatin1String(" where ") + filter; |
|
1217 } |
|
1218 return apply(str, invalidate); |
|
1219 } |
|
1220 } |
|
1221 |
|
1222 /*! |
|
1223 Deletes a record from the database using the cursor's primary |
|
1224 index and the contents of the cursor edit buffer. Returns the |
|
1225 number of records which were deleted. |
|
1226 For error information, use lastError(). |
|
1227 |
|
1228 Only records which meet the filter criteria specified by the |
|
1229 cursor's primary index are deleted. If the cursor does not contain |
|
1230 a primary index, no delete is performed and 0 is returned. If \a |
|
1231 invalidate is true (the default), the current cursor can no longer |
|
1232 be navigated. A new select() call must be made before you can move |
|
1233 to a valid record. For example: |
|
1234 |
|
1235 \snippet doc/src/snippets/code/src_qt3support_sql_q3sqlcursor.cpp 8 |
|
1236 |
|
1237 In the above example, a cursor is created on the 'prices' table |
|
1238 and positioned to the record to be deleted. First primeDelete() is |
|
1239 called to populate the edit buffer with the current cursor values, |
|
1240 e.g. with an id of 999, and then del() is called to actually |
|
1241 delete the record from the database. Remember: all edit operations |
|
1242 (insert(), update() and delete()) operate on the contents of the |
|
1243 cursor edit buffer and not on the contents of the cursor itself. |
|
1244 |
|
1245 \sa primeDelete() setMode() lastError() |
|
1246 */ |
|
1247 |
|
1248 int Q3SqlCursor::del(bool invalidate) |
|
1249 { |
|
1250 QSqlIndex idx = primaryIndex(false); |
|
1251 if (idx.isEmpty()) |
|
1252 return del(qWhereClause(&d->editBuffer, d->nm, QLatin1String("and"), driver()), invalidate); |
|
1253 return del(toString(primaryIndex(), &d->editBuffer, d->nm, QString(QLatin1Char('=')), QLatin1String("and")), invalidate); |
|
1254 } |
|
1255 |
|
1256 /*! |
|
1257 \overload |
|
1258 |
|
1259 Deletes the current cursor record from the database using the |
|
1260 filter \a filter. Only records which meet the filter criteria are |
|
1261 deleted. Returns the number of records which were deleted. If \a |
|
1262 invalidate is true (the default), the current cursor can no longer |
|
1263 be navigated. A new select() call must be made before you can move |
|
1264 to a valid record. For error information, use lastError(). |
|
1265 |
|
1266 The \a filter is an SQL \c WHERE clause, e.g. \c{id=500}. |
|
1267 |
|
1268 \sa setMode() lastError() |
|
1269 */ |
|
1270 |
|
1271 int Q3SqlCursor::del(const QString & filter, bool invalidate) |
|
1272 { |
|
1273 if ((d->md & Delete) != Delete) |
|
1274 return 0; |
|
1275 int k = count(); |
|
1276 if(k == 0) return 0; |
|
1277 QString str = QLatin1String("delete from ") + name(); |
|
1278 if (filter.length()) |
|
1279 str+= QLatin1String(" where ") + filter; |
|
1280 return apply(str, invalidate); |
|
1281 } |
|
1282 |
|
1283 /* |
|
1284 \internal |
|
1285 */ |
|
1286 |
|
1287 int Q3SqlCursor::apply(const QString& q, bool invalidate) |
|
1288 { |
|
1289 int ar = 0; |
|
1290 if (invalidate) { |
|
1291 if (exec(q)) |
|
1292 ar = numRowsAffected(); |
|
1293 } else if (driver()) { |
|
1294 QSqlQuery* sql = d->query(); |
|
1295 if (sql && sql->exec(q)) |
|
1296 ar = sql->numRowsAffected(); |
|
1297 } |
|
1298 return ar; |
|
1299 } |
|
1300 |
|
1301 /* |
|
1302 \internal |
|
1303 */ |
|
1304 |
|
1305 int Q3SqlCursor::applyPrepared(const QString& q, bool invalidate) |
|
1306 { |
|
1307 int ar = 0; |
|
1308 QSqlQuery* sql = 0; |
|
1309 |
|
1310 if (invalidate) { |
|
1311 sql = (QSqlQuery*)this; |
|
1312 d->lastAt = QSql::BeforeFirst; |
|
1313 } else { |
|
1314 sql = d->query(); |
|
1315 } |
|
1316 if (!sql) |
|
1317 return 0; |
|
1318 |
|
1319 if (invalidate || sql->lastQuery() != q) { |
|
1320 if (!sql->prepare(q)) |
|
1321 return 0; |
|
1322 } |
|
1323 |
|
1324 int cnt = 0; |
|
1325 int fieldCount = (int)count(); |
|
1326 for (int j = 0; j < fieldCount; ++j) { |
|
1327 const QSqlField f = d->editBuffer.field(j); |
|
1328 if (d->editBuffer.isGenerated(j)) { |
|
1329 if (f.type() == QVariant::ByteArray) |
|
1330 sql->bindValue(cnt, f.value(), QSql::In | QSql::Binary); |
|
1331 else |
|
1332 sql->bindValue(cnt, f.value()); |
|
1333 cnt++; |
|
1334 } |
|
1335 } |
|
1336 if (sql->exec()) { |
|
1337 ar = sql->numRowsAffected(); |
|
1338 } |
|
1339 return ar; |
|
1340 } |
|
1341 |
|
1342 /*! |
|
1343 Executes the SQL query \a sql. Returns true of the cursor is |
|
1344 active, otherwise returns false. |
|
1345 */ |
|
1346 bool Q3SqlCursor::exec(const QString & sql) |
|
1347 { |
|
1348 d->lastAt = QSql::BeforeFirst; |
|
1349 QSqlQuery::exec(sql); |
|
1350 return isActive(); |
|
1351 } |
|
1352 |
|
1353 /*! |
|
1354 Protected virtual function which is called whenever a field needs |
|
1355 to be calculated. If calculated fields are being used, derived |
|
1356 classes must reimplement this function and return the appropriate |
|
1357 value for field \a name. The default implementation returns an |
|
1358 invalid QVariant. |
|
1359 |
|
1360 \sa setCalculated() |
|
1361 */ |
|
1362 |
|
1363 QVariant Q3SqlCursor::calculateField(const QString&) |
|
1364 { |
|
1365 return QVariant(); |
|
1366 } |
|
1367 |
|
1368 /*! \internal |
|
1369 Ensure fieldlist is synced with query. |
|
1370 |
|
1371 */ |
|
1372 |
|
1373 static QString qTrim(const QString& s) |
|
1374 { |
|
1375 QString result = s; |
|
1376 int end = result.length() - 1; |
|
1377 while (end >= 0 && result[end].isSpace()) // skip white space from end |
|
1378 end--; |
|
1379 result.truncate(end + 1); |
|
1380 return result; |
|
1381 } |
|
1382 |
|
1383 /*! \internal |
|
1384 */ |
|
1385 |
|
1386 void Q3SqlCursor::sync() |
|
1387 { |
|
1388 if (isActive() && isValid() && d->lastAt != at()) { |
|
1389 d->lastAt = at(); |
|
1390 int i = 0; |
|
1391 int j = 0; |
|
1392 bool haveCalculatedFields = false; |
|
1393 for (; i < count(); ++i) { |
|
1394 if (!haveCalculatedFields && d->infoBuffer[i].isCalculated()) { |
|
1395 haveCalculatedFields = true; |
|
1396 } |
|
1397 if (QSqlRecord::isGenerated(i)) { |
|
1398 QVariant v = QSqlQuery::value(j); |
|
1399 if ((v.type() == QVariant::String) && |
|
1400 d->infoBuffer[i].isTrim()) { |
|
1401 v = qTrim(v.toString()); |
|
1402 } |
|
1403 QSqlRecord::setValue(i, v); |
|
1404 if (QSqlQuery::isNull(j)) |
|
1405 QSqlRecord::field(i).clear(); |
|
1406 j++; |
|
1407 } |
|
1408 } |
|
1409 if (haveCalculatedFields) { |
|
1410 for (i = 0; i < count(); ++i) { |
|
1411 if (d->infoBuffer[i].isCalculated()) |
|
1412 QSqlRecord::setValue(i, calculateField(fieldName(i))); |
|
1413 } |
|
1414 } |
|
1415 } |
|
1416 } |
|
1417 |
|
1418 /*! |
|
1419 Returns the value of field number \a i. |
|
1420 */ |
|
1421 |
|
1422 QVariant Q3SqlCursor::value(int i) const |
|
1423 { |
|
1424 const_cast<Q3SqlCursor *>(this)->sync(); |
|
1425 return QSqlRecord::value(i); |
|
1426 } |
|
1427 |
|
1428 /*! \internal |
|
1429 cursors should be filled with Q3SqlFieldInfos... |
|
1430 */ |
|
1431 void Q3SqlCursor::append(const QSqlField& field) |
|
1432 { |
|
1433 append(Q3SqlFieldInfo(field)); |
|
1434 } |
|
1435 |
|
1436 /*! |
|
1437 Returns true if the field \a i is NULL or if there is no field at |
|
1438 position \a i; otherwise returns false. |
|
1439 |
|
1440 This is the same as calling QSqlRecord::isNull(\a i) |
|
1441 */ |
|
1442 bool Q3SqlCursor::isNull(int i) const |
|
1443 { |
|
1444 const_cast<Q3SqlCursor *>(this)->sync(); |
|
1445 return QSqlRecord::isNull(i); |
|
1446 } |
|
1447 /*! |
|
1448 \overload |
|
1449 |
|
1450 Returns true if the field called \a name is NULL or if there is no |
|
1451 field called \a name; otherwise returns false. |
|
1452 |
|
1453 This is the same as calling QSqlRecord::isNull(\a name) |
|
1454 */ |
|
1455 bool Q3SqlCursor::isNull(const QString& name) const |
|
1456 { |
|
1457 const_cast<Q3SqlCursor *>(this)->sync(); |
|
1458 return QSqlRecord::isNull(name); |
|
1459 } |
|
1460 |
|
1461 /*! \internal */ |
|
1462 void Q3SqlCursor::setValue(int i, const QVariant& val) |
|
1463 { |
|
1464 sync(); |
|
1465 #ifdef QT_DEBUG |
|
1466 qDebug("Q3SqlCursor::setValue(): This will not affect actual database values. Use primeInsert(), primeUpdate() or primeDelete()."); |
|
1467 #endif |
|
1468 QSqlRecord::setValue(i, val); |
|
1469 } |
|
1470 |
|
1471 /*! \internal */ |
|
1472 bool Q3SqlCursor::seek(int i, bool relative) |
|
1473 { |
|
1474 bool res = QSqlQuery::seek(i, relative); |
|
1475 sync(); |
|
1476 return res; |
|
1477 } |
|
1478 |
|
1479 /*! \internal */ |
|
1480 bool Q3SqlCursor::next() |
|
1481 { |
|
1482 bool res = QSqlQuery::next(); |
|
1483 sync(); |
|
1484 return res; |
|
1485 } |
|
1486 |
|
1487 /*! |
|
1488 \fn Q3SqlCursor::previous() |
|
1489 |
|
1490 \internal |
|
1491 */ |
|
1492 |
|
1493 /*! \internal */ |
|
1494 bool Q3SqlCursor::prev() |
|
1495 { |
|
1496 bool res = QSqlQuery::previous(); |
|
1497 sync(); |
|
1498 return res; |
|
1499 } |
|
1500 |
|
1501 /*! \internal */ |
|
1502 bool Q3SqlCursor::first() |
|
1503 { |
|
1504 bool res = QSqlQuery::first(); |
|
1505 sync(); |
|
1506 return res; |
|
1507 } |
|
1508 |
|
1509 /*! \internal */ |
|
1510 bool Q3SqlCursor::last() |
|
1511 { |
|
1512 bool res = QSqlQuery::last(); |
|
1513 sync(); |
|
1514 return res; |
|
1515 } |
|
1516 |
|
1517 QT_END_NAMESPACE |
|
1518 |
|
1519 #endif |