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[Feature][PostgreSQL] Compile expression functions

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rldhont committed Jan 2, 2017
1 parent cd970f2 commit 735b1c359a4b3941aa84b9b7f051352c9c714648
@@ -319,13 +319,60 @@ QgsSqlExpressionCompiler::Result QgsSqlExpressionCompiler::compileNode( const Qg
}

case QgsExpression::ntFunction:
{
const QgsExpression::NodeFunction* n = static_cast<const QgsExpression::NodeFunction*>( node );
QgsExpression::Function* fd = QgsExpression::Functions()[n->fnIndex()];

// get sql function to compile node expression
QString nd = sqlFunctionFromFunctionName( fd->name() );
// if no sql function the node can't be compiled
if ( nd.isEmpty() )
return Fail;

// compile arguments
QStringList args;
Result inResult = Complete;
Q_FOREACH ( const QgsExpression::Node* ln, n->args()->list() )
{
QString s;
Result r = compileNode( ln, s );
if ( r == Complete || r == Partial )
{
args << s;
if ( r == Partial )
inResult = Partial;
}
else
return r;
}

// update arguments to be adapted to SQL function
args = sqlArgumentsFromFunctionName( fd->name(), args );

// build result
result = QStringLiteral( "%1(%2)" ).arg( nd, args.join( ',' ) );
return inResult == Partial ? Partial : Complete;
}

case QgsExpression::ntCondition:
break;
}

return Fail;
}

QString QgsSqlExpressionCompiler::sqlFunctionFromFunctionName( const QString& fnName ) const
{
Q_UNUSED( fnName );
return QString();
}

QStringList QgsSqlExpressionCompiler::sqlArgumentsFromFunctionName( const QString& fnName, const QStringList& fnArgs ) const
{
Q_UNUSED( fnName );
return QStringList( fnArgs );
}

bool QgsSqlExpressionCompiler::nodeIsNullLiteral( const QgsExpression::Node* node ) const
{
if ( node->nodeType() != QgsExpression::ntLiteral )
@@ -93,6 +93,21 @@ class CORE_EXPORT QgsSqlExpressionCompiler
*/
virtual Result compileNode( const QgsExpression::Node* node, QString& str );

/** Return the SQL function for the expression function.
* Derived classes should override this to help compile functions
* @param fnName expression function name
* @returns the SQL function name
*/
virtual QString sqlFunctionFromFunctionName( const QString& fnName ) const;

/** Return the Arguments for SQL function for the expression function.
* Derived classes should override this to help compile functions
* @param fnName expression function name
* @param fnArgs arguments from expression
* @returns the arguments updated for SQL Function
*/
virtual QStringList sqlArgumentsFromFunctionName( const QString& fnName, const QStringList& fnArgs ) const;

QString mResult;
QgsFields mFields;

@@ -18,6 +18,12 @@

QgsPostgresExpressionCompiler::QgsPostgresExpressionCompiler( QgsPostgresFeatureSource* source )
: QgsSqlExpressionCompiler( source->mFields )
, mGeometryColumn( source->mGeometryColumn )
, mSpatialColType( source->mSpatialColType )
, mDetectedGeomType( source->mDetectedGeomType )
, mRequestedGeomType( source->mRequestedGeomType )
, mRequestedSrid( source->mRequestedSrid )
, mDetectedSrid( source->mDetectedSrid )
{
}

@@ -32,3 +38,150 @@ QString QgsPostgresExpressionCompiler::quotedValue( const QVariant& value, bool&
return QgsPostgresConn::quotedValue( value );
}

static const QMap<QString, QString>& functionNamesSqlFunctionsMap()
{
static QMap<QString, QString> fnNames;
if ( fnNames.isEmpty() )
{
fnNames =
{
{ "sqrt", "sqrt" },
{ "radians", "radians" },
{ "degrees", "degrees" },
{ "abs", "abs" },
{ "cos", "cos" },
{ "sin", "sin" },
{ "tan", "tan" },
{ "acos", "acos" },
{ "asin", "asin" },
{ "atan", "atan" },
{ "atan2", "atan2" },
{ "exp", "exp" },
{ "ln", "ln" },
{ "log", "log" },
{ "log10", "log" },
{ "round", "round" },
{ "floor", "floor" },
{ "ceil", "ceil" },
{ "pi", "pi" },
// geometry functions
//{ "azimuth", "ST_Azimuth" },
{ "x", "ST_X" },
{ "y", "ST_Y" },
//{ "z", "ST_Z" },
//{ "m", "ST_M" },
{ "x_min", "ST_XMin" },
{ "y_min", "ST_YMin" },
{ "x_max", "ST_XMax" },
{ "y_max", "ST_YMax" },
{ "area", "ST_Area" },
{ "perimeter", "ST_Perimeter" },
{ "relate", "ST_Relate" },
{ "disjoint", "ST_Disjoint" },
{ "intersects", "ST_Intersects" },
//{ "touches", "ST_Touches" },
{ "crosses", "ST_Crosses" },
{ "contains", "ST_Contains" },
{ "overlaps", "ST_Overlaps" },
{ "within", "ST_Within" },
{ "translate", "ST_Translate" },
{ "buffer", "ST_Buffer" },
{ "centroid", "ST_Centroid" },
{ "point_on_surface", "ST_PointOnSurface" },
//{ "reverse", "ST_Reverse" },
//{ "is_closed", "ST_IsClosed" },
//{ "convex_hull", "ST_ConvexHull" },
//{ "difference", "ST_Difference" },
{ "distance", "ST_Distance" },
//{ "intersection", "ST_Intersection" },
//{ "sym_difference", "ST_SymDifference" },
//{ "combine", "ST_Union" },
//{ "union", "ST_Union" },
{ "geom_from_wkt", "ST_GeomFromText" },
{ "geom_from_gml", "ST_GeomFromGML" }
};
}
return fnNames;
}

QString QgsPostgresExpressionCompiler::sqlFunctionFromFunctionName( const QString& fnName ) const
{
return functionNamesSqlFunctionsMap().value( fnName, QString() );
}

QStringList QgsPostgresExpressionCompiler::sqlArgumentsFromFunctionName( const QString& fnName, const QStringList& fnArgs ) const
{
QStringList args( fnArgs );
if ( fnName == "geom_from_wkt" )
{
args << ( mRequestedSrid.isEmpty() ? mDetectedSrid : mRequestedSrid );
}
else if ( fnName == "geom_from_gml" )
{
args << ( mRequestedSrid.isEmpty() ? mDetectedSrid : mRequestedSrid );
}
else if ( fnName == "x" || fnName == "y" )
{
args = QStringList( QStringLiteral( "ST_Centroid(%1)" ).arg( args[0] ) );
}
else if ( fnName == "buffer" && args.length() == 2 )
{
args << "8";
}
// x and y functions have to be adapted
return args;
}

QgsSqlExpressionCompiler::Result QgsPostgresExpressionCompiler::compileNode( const QgsExpression::Node* node, QString& result )
{
switch ( node->nodeType() )
{
case QgsExpression::ntFunction:
{
const QgsExpression::NodeFunction* n = static_cast<const QgsExpression::NodeFunction*>( node );

QgsExpression::Function* fd = QgsExpression::Functions()[n->fnIndex()];
if ( fd->name() == "$geometry" )
{
result = quotedIdentifier( mGeometryColumn );
return Complete;
}
/*
* These methods are tricky
* QGIS expression versions of these return ellipsoidal measurements
* based on the project settings, and also convert the result to the
* units specified in project properties.
else if ( fd->name() == "$area" )
{
result = QStringLiteral( "ST_Area(%1)" ).arg( quotedIdentifier( mGeometryColumn ) );
return Complete;
}
else if ( fd->name() == "$length" )
{
result = QStringLiteral( "ST_Length(%1)" ).arg( quotedIdentifier( mGeometryColumn ) );
return Complete;
}
else if ( fd->name() == "$perimeter" )
{
result = QStringLiteral( "ST_Perimeter(%1)" ).arg( quotedIdentifier( mGeometryColumn ) );
return Complete;
}
else if ( fd->name() == "$x" )
{
result = QStringLiteral( "ST_X(%1)" ).arg( quotedIdentifier( mGeometryColumn ) );
return Complete;
}
else if ( fd->name() == "$y" )
{
result = QStringLiteral( "ST_Y(%1)" ).arg( quotedIdentifier( mGeometryColumn ) );
return Complete;
}
*/
}

default:
return QgsSqlExpressionCompiler::compileNode( node, result );
}

return Fail;
}
@@ -18,6 +18,7 @@

#include "qgssqlexpressioncompiler.h"
#include "qgsexpression.h"
#include "qgspostgresconn.h"
#include "qgspostgresfeatureiterator.h"

class QgsPostgresExpressionCompiler : public QgsSqlExpressionCompiler
@@ -30,6 +31,16 @@ class QgsPostgresExpressionCompiler : public QgsSqlExpressionCompiler

virtual QString quotedIdentifier( const QString& identifier ) override;
virtual QString quotedValue( const QVariant& value, bool& ok ) override;
virtual Result compileNode( const QgsExpression::Node* node, QString& str ) override;
virtual QString sqlFunctionFromFunctionName( const QString& fnName ) const override;
virtual QStringList sqlArgumentsFromFunctionName( const QString& fnName, const QStringList& fnArgs ) const override;

QString mGeometryColumn;
QgsPostgresGeometryColumnType mSpatialColType;
QgsWkbTypes::Type mDetectedGeomType;
QgsWkbTypes::Type mRequestedGeomType;
QString mRequestedSrid;
QString mDetectedSrid;
};

#endif // QGSPOSTGRESEXPRESSIONCOMPILER_H
@@ -94,7 +94,7 @@ def disableCompiler(self):
QSettings().setValue('/qgis/compileExpressions', False)

def uncompiledFilters(self):
return set(['intersects($geometry,geom_from_wkt( \'Polygon ((-72.2 66.1, -65.2 66.1, -65.2 72.0, -72.2 72.0, -72.2 66.1))\'))'])
return set([])

def partiallyCompiledFilters(self):
return set([])
@@ -664,7 +664,7 @@ def disableCompiler(self):
QSettings().setValue('/qgis/compileExpressions', False)

def uncompiledFilters(self):
return set(['intersects($geometry,geom_from_wkt( \'Polygon ((-72.2 66.1, -65.2 66.1, -65.2 72.0, -72.2 72.0, -72.2 66.1))\'))'])
return set([])

def partiallyCompiledFilters(self):
return set([])

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