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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 documentation 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 /*! |
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43 \class Q3SqlFieldInfo |
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44 \brief The Q3SqlFieldInfo class stores meta data associated with a SQL field. |
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45 |
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46 \compat |
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47 |
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48 Q3SqlFieldInfo objects only store meta data; field values are |
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49 stored in QSqlField objects. |
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50 |
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51 All values must be set in the constructor, and may be retrieved |
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52 using isRequired(), type(), length(), precision(), defaultValue(), |
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53 name(), isGenerated() and typeID(). |
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54 |
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55 \sa Q3SqlRecordInfo |
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56 */ |
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57 |
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58 /*! |
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59 \fn Q3SqlFieldInfo::Q3SqlFieldInfo(const QString& name, |
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60 QVariant::Type typ, |
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61 int required, |
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62 int len, |
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63 int prec, |
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64 const QVariant& defValue, |
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65 int typeID, |
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66 bool generated, |
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67 bool trim, |
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68 bool calculated) |
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69 |
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70 Constructs a Q3SqlFieldInfo with the following parameters: |
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71 \table |
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72 \row \i \a name \i the name of the field. |
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73 \row \i \a typ \i the field's type in a QVariant. |
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74 \row \i \a required \i greater than 0 if the field is required, 0 |
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75 if its value can be NULL and less than 0 if it cannot be |
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76 determined whether the field is required or not. |
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77 \row \i \a len \i the length of the field. Note that for |
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78 non-character types some databases return either the length in |
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79 bytes or the number of digits. -1 signifies that the length cannot |
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80 be determined. |
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81 \row \i \a prec \i the precision of the field, or -1 if the field |
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82 has no precision or it cannot be determined. |
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83 \row \i \a defValue \i the default value that is inserted into |
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84 the table if none is specified by the user. QVariant() if there is |
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85 no default value or it cannot be determined. |
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86 \row \i \a typeID \i the internal typeID of the database system |
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87 (only useful for low-level programming). 0 if unknown. |
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88 \row \i \a generated \i TRUE indicates that this field should be |
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89 included in auto-generated SQL statments, e.g. in Q3SqlCursor. |
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90 \row \i \a trim \i TRUE indicates that widgets should remove |
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91 trailing whitespace from character fields. This does not affect |
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92 the field value but only its representation inside widgets. |
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93 \row \i \a calculated \i TRUE indicates that the value of this |
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94 field is calculated. The value of calculated fields can by |
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95 modified by subclassing Q3SqlCursor and overriding |
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96 Q3SqlCursor::calculateField(). |
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97 \endtable |
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98 */ |
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99 |
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100 /*! |
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101 \fn Q3SqlFieldInfo::~Q3SqlFieldInfo() |
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102 |
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103 Destroys the object and frees any allocated resources. |
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104 */ |
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105 |
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106 /*! |
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107 \fn Q3SqlFieldInfo::Q3SqlFieldInfo(const QSqlField & other) |
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108 |
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109 Creates a Q3SqlFieldInfo object with the type and the name of the |
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110 QSqlField \a other. |
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111 */ |
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112 |
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113 /*! |
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114 \fn bool Q3SqlFieldInfo::operator==(const Q3SqlFieldInfo& other) const |
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115 |
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116 Assigns \a other to this field info and returns a reference to it. |
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117 */ |
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118 |
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119 /*! |
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120 \fn QSqlField Q3SqlFieldInfo::toField() const |
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121 |
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122 Returns an empty QSqlField based on the information in this |
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123 Q3SqlFieldInfo. |
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124 */ |
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125 |
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126 /*! |
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127 \fn int Q3SqlFieldInfo::isRequired() const |
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128 |
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129 Returns a value greater than 0 if the field is required (NULL |
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130 values are not allowed), 0 if it isn't required (NULL values are |
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131 allowed) or less than 0 if it cannot be determined whether the |
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132 field is required or not. |
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133 */ |
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134 |
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135 /*! |
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136 \fn QVariant::Type Q3SqlFieldInfo::type() const |
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137 |
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138 Returns the field's type or QVariant::Invalid if the type is |
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139 unknown. |
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140 */ |
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141 |
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142 /*! |
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143 \fn int Q3SqlFieldInfo::length() const |
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144 |
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145 Returns the field's length. For fields storing text the return |
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146 value is the maximum number of characters the field can hold. For |
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147 non-character fields some database systems return the number of |
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148 bytes needed or the number of digits allowed. If the length cannot |
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149 be determined -1 is returned. |
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150 */ |
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151 |
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152 /*! |
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153 \fn int Q3SqlFieldInfo::precision() const |
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154 |
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155 Returns the field's precision or -1 if the field has no precision |
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156 or it cannot be determined. |
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157 */ |
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158 |
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159 /*! |
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160 \fn QVariant Q3SqlFieldInfo::defaultValue() const |
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161 |
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162 Returns the field's default value or an empty QVariant if the |
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163 field has no default value or the value couldn't be determined. |
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164 The default value is the value inserted in the database when it |
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165 is not explicitly specified by the user. |
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166 */ |
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167 |
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168 /*! |
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169 \fn QString Q3SqlFieldInfo::name() const |
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170 |
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171 Returns the name of the field in the SQL table. |
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172 */ |
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173 |
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174 /*! |
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175 \fn int Q3SqlFieldInfo::typeID() const |
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176 |
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177 Returns the internal type identifier as returned from the database |
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178 system. The return value is 0 if the type is unknown. |
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179 */ |
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180 |
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181 /*! |
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182 \fn bool Q3SqlFieldInfo::isGenerated() const |
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183 |
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184 Returns TRUE if the field should be included in auto-generated |
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185 SQL statments, e.g. in Q3SqlCursor; otherwise returns FALSE. |
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186 |
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187 \sa setGenerated() |
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188 */ |
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189 |
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190 /*! |
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191 \fn bool Q3SqlFieldInfo::isTrim() const |
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192 |
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193 Returns TRUE if trailing whitespace should be removed from |
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194 character fields; otherwise returns FALSE. |
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195 |
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196 \sa setTrim() |
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197 */ |
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198 |
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199 /*! |
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200 \fn bool Q3SqlFieldInfo::isCalculated() const |
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201 |
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202 Returns TRUE if the field is calculated; otherwise returns FALSE. |
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203 |
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204 \sa setCalculated() |
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205 */ |
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206 |
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207 /*! |
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208 \fn void Q3SqlFieldInfo::setTrim(bool trim) |
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209 |
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210 If \a trim is TRUE widgets should remove trailing whitespace from |
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211 character fields. This does not affect the field value but only |
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212 its representation inside widgets. |
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213 |
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214 \sa isTrim() |
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215 */ |
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216 |
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217 /*! |
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218 \fn void Q3SqlFieldInfo::setGenerated(bool generated) |
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219 |
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220 \a generated set to FALSE indicates that this field should not appear |
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221 in auto-generated SQL statements (for example in Q3SqlCursor). |
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222 |
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223 \sa isGenerated() |
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224 */ |
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225 |
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226 /*! |
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227 \fn void Q3SqlFieldInfo::setCalculated(bool calculated) |
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228 |
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229 \a calculated set to TRUE indicates that this field is a calculated |
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230 field. The value of calculated fields can by modified by subclassing |
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231 Q3SqlCursor and overriding Q3SqlCursor::calculateField(). |
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232 |
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233 \sa isCalculated() |
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234 */ |