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1 // Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies). |
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2 // All rights reserved. |
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3 // This component and the accompanying materials are made available |
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4 // under the terms of "Eclipse Public License v1.0" |
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5 // which accompanies this distribution, and is available |
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6 // at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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7 // |
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8 // Initial Contributors: |
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9 // Nokia Corporation - initial contribution. |
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10 // |
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11 // Contributors: |
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12 // |
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13 // Description: |
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14 // |
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15 |
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16 #ifndef __SQLSTATEMENTIMPL_H__ |
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17 #define __SQLSTATEMENTIMPL_H__ |
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18 |
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19 #include "SqlBufIterator.h" //TSqlBufFlat, TSqlBufRIterator, TSqlBufWIterator |
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20 #include "SqlDatabaseImpl.h"//CSqlDatabaseImpl |
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21 #include "SqlStmtSession.h" //RSqlStatementSession |
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22 |
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23 //Forward declarations |
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24 class MStreamBuf; |
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25 class CSqlStatementImpl; |
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26 |
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27 #ifdef _DEBUG |
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28 #define LONGCOL_INVARIANT() Invariant() |
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29 #else |
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30 #define LONGCOL_INVARIANT() |
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31 #endif |
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32 |
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33 /** |
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34 RSqlLongColumnColl class represents a collection of long text/binary column values. |
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35 Once a column value is added to the collection, it is guaranteed that the memory address of the |
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36 column value will never change. |
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37 The class was designed to solve one specific problem - to exclude the possibility that SQL clients |
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38 may get a dangling pointer to a block of memory which already has been deleted. |
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39 Without RSqlLongColumnColl class, it may happen for example, when client prepares a SELECT sql |
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40 statement, where the record consists of two long binary/text column values. |
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41 The client calls RSqlStatement::Next() to move to a record. Since the column values are long, they will |
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42 not be transferred on the client side by the Next() call, so the client side row buffer (CSqlStatementImpl::iColumnValueBuf) |
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43 will mark them as "not present". |
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44 Then the client calls RSqlStatement::ColumnBinary(0, TPtrC8&) to get a pointer to the first column value. |
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45 The row buffer is reallocated, and the column value is retrieved from the server and copied into the buffer, the client's pointer |
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46 is set to point to the place in the row buffer, where the column value is. |
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47 While keeping the pointer to the first column value, the client calls again RSqlStatement::ColumnBinary(1, TPtrC8&) to retrieve |
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48 the second column value. In which case, the row buffer may get reallocated again, so the first pointer will point to a |
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49 block of memory, which has been deleted. |
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50 With the implementation and use of RSqlLongColumnColl class, the long column values will be kept in a different place, |
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51 RSqlLongColumnColl's collection, where it is guaranteed that the memory address of the column value is constant. |
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52 |
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53 @internalComponent |
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54 */ |
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55 NONSHARABLE_CLASS(RSqlLongColumnColl) |
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56 { |
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57 public: |
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58 struct TColumnReader |
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59 { |
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60 virtual TInt Read(TInt aColumnIndex, TDes8& aBuf) = 0; |
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61 }; |
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62 |
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63 public: |
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64 inline RSqlLongColumnColl(); |
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65 inline void Close(); |
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66 inline void Reset(); |
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67 TInt Append(TColumnReader& aReader, TInt aColumnIndex, TInt aColumnSize); |
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68 inline TPtrC Text(TInt aColumnIndex) const; |
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69 inline TPtrC8 Binary(TInt aColumnIndex) const; |
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70 inline TBool IsPresent(TInt aColumnIndex) const; |
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71 |
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72 private: |
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73 inline TInt FindValue(TInt aColumnIndex) const; |
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74 #ifdef _DEBUG |
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75 void Invariant() const; |
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76 #endif |
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77 |
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78 private: |
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79 struct TData |
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80 { |
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81 static TBool Compare(const TInt* aIndex, const TData& aData); |
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82 inline TData(TInt aIndex, HBufC8* aData); |
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83 TInt iIndex; |
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84 HBufC8* iData; |
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85 }; |
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86 enum {KLongColumnCollGranularity = 8}; |
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87 RArray<TData> iValues; |
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88 |
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89 }; |
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90 |
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91 template <class DES> TInt SqlCreateStatement(CSqlStatementImpl*& aImpl, CSqlDatabaseImpl& aDatabase, const DES& aSqlStmt); |
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92 |
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93 /** |
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94 CSqlStatementImpl implements RSqlStatement functionality. |
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95 CSqlStatementImpl can prepare and execute parametrized SQL statements and SQL statements without parameters. |
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96 CSqlStatementImpl cannot prepare and execute SQL strings containing more than one SQL statement. |
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97 @internalComponent |
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98 */ |
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99 NONSHARABLE_CLASS(CSqlStatementImpl) : public CBase |
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100 { |
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101 template <class DES> friend TInt SqlCreateStatement(CSqlStatementImpl*& aImpl, CSqlDatabaseImpl& aDatabase, const DES& aSqlStmt); |
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102 |
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103 public: |
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104 static inline TInt New(CSqlStatementImpl*& aImpl, CSqlDatabaseImpl& aDatabase, const TDesC16& aSqlStmt); |
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105 static inline TInt New(CSqlStatementImpl*& aImpl, CSqlDatabaseImpl& aDatabase, const TDesC8& aSqlStmt); |
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106 virtual ~CSqlStatementImpl(); |
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107 |
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108 inline TBool AtRow() const; |
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109 |
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110 TInt Reset(); |
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111 TInt Exec(); |
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112 void Exec(TRequestStatus& aStatus); |
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113 TInt Next(); |
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114 |
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115 TInt BindNull(TInt aParamIndex); |
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116 TInt BindInt(TInt aParamIndex, TInt aParamValue); |
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117 TInt BindInt64(TInt aParamIndex, TInt64 aParamValue); |
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118 TInt BindReal(TInt aParamIndex, TReal aParamValue); |
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119 TInt BindText(TInt aParamIndex, const TDesC& aParamText); |
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120 TInt BindBinary(TInt aParamIndex, const TDesC8& aParamData); |
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121 TInt BindZeroBlob(TInt aParamIndex, TInt aBlobSize); |
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122 |
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123 inline TInt ColumnCount() const; |
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124 TSqlColumnType ColumnType(TInt aColumnIndex); |
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125 TInt DeclaredColumnType(TInt aColumnIndex, TSqlColumnType& aColumnType); |
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126 TInt ColumnSize(TInt aColumnIndex); |
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127 TInt ColumnInt(TInt aColumnIndex); |
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128 TInt64 ColumnInt64(TInt aColumnIndex); |
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129 TReal ColumnReal(TInt aColumnIndex); |
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130 TInt ColumnText(TInt aColumnIndex, TPtrC& aPtr); |
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131 TInt ColumnText(TInt aColumnIndex, TDes& aDest); |
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132 TInt ColumnBinary(TInt aColumnIndex, TPtrC8& aPtr); |
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133 TInt ColumnBinary(TInt aColumnIndex, TDes8& aDest); |
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134 |
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135 TInt ColumnName(TInt aColumnIndex, TPtrC& aNameDest); |
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136 TInt ParameterName(TInt aParamIndex, TPtrC& aNameDest); |
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137 |
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138 inline TInt ParamIndex(const TDesC& aParamName); |
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139 inline TInt ColumnIndex(const TDesC& aColumnName); |
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140 |
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141 inline MStreamBuf* ColumnSourceL(TInt aColumnIndex); |
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142 inline MStreamBuf* ParamSinkL(TSqlSrvFunction aFunction, TInt aParamIndex); |
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143 |
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144 HBufC* GetDeclColumnTypesL(); |
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145 |
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146 private: |
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147 inline CSqlStatementImpl(); |
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148 template <class DES> TInt Construct(CSqlDatabaseImpl& aDatabase, const DES& aSqlStmt); |
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149 TInt Name2Index(const TDesC& aName, RSqlBufFlat& aNameBufFlat, TInt aCount, TSqlSrvFunction aFunction, TBool& aPresent); |
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150 TInt Index2Name(TInt aIndex, RSqlBufFlat& aNameBufFlat, TInt aCount, TSqlSrvFunction aFunction, TBool& aPresent, TPtrC& aColName); |
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151 TInt CheckNameBufPresent(TBool& aPresent, RSqlBufFlat& aNameBufFlat, TInt aCount, TSqlSrvFunction aFunction); |
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152 |
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153 private: |
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154 RSqlStatementSession iSqlStmtSession; |
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155 TBool iBound; |
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156 enum TState {EUnknown, EAtRow}; |
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157 TState iState; |
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158 |
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159 TInt iColumnCnt; |
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160 TBool iColumnNameBufPresent; |
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161 RSqlBufFlat iColumnNameBuf; |
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162 RSqlBufFlat iColumnValueBuf; |
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163 TSqlBufRIterator iColumnValBufIt; |
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164 |
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165 TInt iParamCnt; |
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166 TBool iParamNameBufPresent; |
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167 RSqlBufFlat iParamNameBuf; |
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168 RSqlBufFlat iParamValueBuf; |
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169 TSqlBufWIterator iParamValBufIt; |
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170 |
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171 RSqlLongColumnColl iLongColumnColl; |
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172 |
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173 RArray<TSqlColumnType> iDeclaredColumnTypes; //Array of declared column types for current statement. |
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174 }; |
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175 |
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176 #include "SqlStatementImpl.inl" |
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177 |
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178 #endif //__SQLSTATEMENTIMPL_H__ |