QGIS API Documentation 3.39.0-Master (73c886ac97c)
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qgssqlexpressioncompiler.h
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1/***************************************************************************
2 qgssqlexpressioncompiler.h
3 --------------------------
4 begin : November 2015
5 copyright : (C) 2015 Nyall Dawson
6 email : nyall dot dawson at gmail dot com
7 ***************************************************************************
8 * *
9 * This program is free software; you can redistribute it and/or modify *
10 * it under the terms of the GNU General Public License as published by *
11 * the Free Software Foundation; either version 2 of the License, or *
12 * (at your option) any later version. *
13 * *
14 ***************************************************************************/
15
16#ifndef QGSSQLEXPRESSIONCOMPILER_H
17#define QGSSQLEXPRESSIONCOMPILER_H
18
19#define SIP_NO_FILE
20
21#include "qgis_core.h"
22#include "qgsfields.h"
24
25class QgsExpression;
27
39class CORE_EXPORT QgsSqlExpressionCompiler
40{
41 public:
42
44 enum Result
45 {
49 Fail
50 };
51
55 enum Flag
56 {
57 CaseInsensitiveStringMatch = 1,
58 LikeIsCaseInsensitive = 1 << 1,
59 NoNullInBooleanLogic = 1 << 2,
60 NoUnaryMinus = 1 << 3,
61 IntegerDivisionResultsInInteger = 1 << 4,
62 };
63 Q_DECLARE_FLAGS( Flags, Flag )
64
65
73 explicit QgsSqlExpressionCompiler( const QgsFields &fields, QgsSqlExpressionCompiler::Flags flags = Flags(), bool ignoreStaticNodes = false );
74 virtual ~QgsSqlExpressionCompiler() = default;
75
79 virtual Result compile( const QgsExpression *exp );
80
84 virtual QString result();
85
100 bool opIsStringComparison( QgsExpressionNodeBinaryOperator::BinaryOperator op );
101
102 protected:
103
110 virtual QString quotedIdentifier( const QString &identifier );
111
119 virtual QString quotedValue( const QVariant &value, bool &ok );
120
127 virtual Result compileNode( const QgsExpressionNode *node, QString &str );
128
135 virtual QString sqlFunctionFromFunctionName( const QString &fnName ) const;
136
144 virtual QStringList sqlArgumentsFromFunctionName( const QString &fnName, const QStringList &fnArgs ) const;
145
151 virtual QString castToReal( const QString &value ) const;
152
168 virtual QString castToText( const QString &value ) const;
169
174 virtual QString castToInt( const QString &value ) const;
175
181 virtual Result replaceNodeByStaticCachedValueIfPossible( const QgsExpressionNode *node, QString &str );
182
183 QString mResult;
185
186 private:
187
188 Flags mFlags;
189
190 bool mIgnoreStaticNodes = false;
191
192 bool nodeIsNullLiteral( const QgsExpressionNode *node ) const;
193
194};
195
197
198#endif // QGSSQLEXPRESSIONCOMPILER_H
Abstract base class for all nodes that can appear in an expression.
Class for parsing and evaluation of expressions (formerly called "search strings").
Container of fields for a vector layer.
Definition qgsfields.h:46
Generic expression compiler for translation to provider specific SQL WHERE clauses.
Result
Possible results from expression compilation.
@ Complete
Expression was successfully compiled and can be completely delegated to provider.
@ Partial
Expression was partially compiled, but provider will return extra records and results must be double-...
virtual ~QgsSqlExpressionCompiler()=default
Flag
Enumeration of flags for how provider handles SQL clauses.
#define str(x)
Definition qgis.cpp:38
Q_DECLARE_OPERATORS_FOR_FLAGS(QgsTextRendererUtils::CurvedTextFlags)