postgres provider: use min()/max() before casting (followup bf56457; fixes #12306)

jef-n · jef-n · commit 377c1dba6222 · 2015-03-04T08:31:12.000+01:00
(cherry picked from commit 7ce195ebec7330f101bb6922055a079958bfd58a)
diff --git a/src/providers/postgres/qgspostgresconn.cpp b/src/providers/postgres/qgspostgresconn.cpp
@@ -1170,34 +1170,35 @@ qint64 QgsPostgresConn::getBinaryInt( QgsPostgresResult &queryResult, int row, i
   return oid;
 }
 
-QString QgsPostgresConn::fieldExpression( const QgsField &fld )
+QString QgsPostgresConn::fieldExpression( const QgsField &fld, QString expr )
 {
   const QString &type = fld.typeName();
+  expr = expr.arg( quotedIdentifier( fld.name() ) );
   if ( type == "money" )
   {
-    return QString( "cash_out(%1)" ).arg( quotedIdentifier( fld.name() ) );
+    return QString( "cash_out(%1)" ).arg( expr );
   }
   else if ( type.startsWith( "_" ) )
   {
-    return QString( "array_out(%1)" ).arg( quotedIdentifier( fld.name() ) );
+    return QString( "array_out(%1)" ).arg( expr );
   }
   else if ( type == "bool" )
   {
-    return QString( "boolout(%1)" ).arg( quotedIdentifier( fld.name() ) );
+    return QString( "boolout(%1)" ).arg( expr );
   }
   else if ( type == "geometry" )
   {
     return QString( "%1(%2)" )
            .arg( majorVersion() < 2 ? "asewkt" : "st_asewkt" )
-           .arg( quotedIdentifier( fld.name() ) );
+           .arg( expr );
   }
   else if ( type == "geography" )
   {
-    return QString( "st_astext(%1)" ).arg( quotedIdentifier( fld.name() ) );
+    return QString( "st_astext(%1)" ).arg( expr );
   }
   else
   {
-    return quotedIdentifier( fld.name() ) + "::text";
+    return expr + "::text";
   }
 }
 
diff --git a/src/providers/postgres/qgspostgresconn.h b/src/providers/postgres/qgspostgresconn.h
@@ -285,7 +285,7 @@ class QgsPostgresConn : public QObject
 
     qint64 getBinaryInt( QgsPostgresResult &queryResult, int row, int col );
 
-    QString fieldExpression( const QgsField &fld );
+    QString fieldExpression( const QgsField &fld, QString expr = "%1" );
 
     QString connInfo() const { return mConnInfo; }
 
diff --git a/src/providers/postgres/qgspostgresprovider.cpp b/src/providers/postgres/qgspostgresprovider.cpp
@@ -1234,8 +1234,8 @@ QVariant QgsPostgresProvider::minimumValue( int index )
   {
     // get the field name
     const QgsField &fld = field( index );
-    QString sql = QString( "SELECT min(%1) FROM %2" )
-                  .arg( connectionRO()->fieldExpression( fld ) )
+    QString sql = QString( "SELECT %1 FROM %2" )
+                  .arg( connectionRO()->fieldExpression( fld, "min(%1)" ) )
                   .arg( mQuery );
 
     if ( !mSqlWhereClause.isEmpty() )
@@ -1407,8 +1407,8 @@ QVariant QgsPostgresProvider::maximumValue( int index )
   {
     // get the field name
     const QgsField &fld = field( index );
-    QString sql = QString( "SELECT max(%1) FROM %2" )
-                  .arg( connectionRO()->fieldExpression( fld ) )
+    QString sql = QString( "SELECT %1 FROM %2" )
+                  .arg( connectionRO()->fieldExpression( fld, "max(%1)" ) )
                   .arg( mQuery );
 
     if ( !mSqlWhereClause.isEmpty() )

Original file line number	Diff line number	Diff line change
`@@ -1170,34 +1170,35 @@ qint64 QgsPostgresConn::getBinaryInt( QgsPostgresResult &queryResult, int row, i`
`1170`	`1170`	`return oid;`
`1171`	`1171`	`}`
`1172`	`1172`
`1173`		`-QString QgsPostgresConn::fieldExpression( const QgsField &fld )`
	`1173`	`+QString QgsPostgresConn::fieldExpression( const QgsField &fld, QString expr )`
`1174`	`1174`	`{`
`1175`	`1175`	`const QString &type = fld.typeName();`
	`1176`	`+ expr = expr.arg( quotedIdentifier( fld.name() ) );`
`1176`	`1177`	`if ( type == "money" )`
`1177`	`1178`	`{`
`1178`		`- return QString( "cash_out(%1)" ).arg( quotedIdentifier( fld.name() ) );`
	`1179`	`+ return QString( "cash_out(%1)" ).arg( expr );`
`1179`	`1180`	`}`
`1180`	`1181`	`else if ( type.startsWith( "_" ) )`
`1181`	`1182`	`{`
`1182`		`- return QString( "array_out(%1)" ).arg( quotedIdentifier( fld.name() ) );`
	`1183`	`+ return QString( "array_out(%1)" ).arg( expr );`
`1183`	`1184`	`}`
`1184`	`1185`	`else if ( type == "bool" )`
`1185`	`1186`	`{`
`1186`		`- return QString( "boolout(%1)" ).arg( quotedIdentifier( fld.name() ) );`
	`1187`	`+ return QString( "boolout(%1)" ).arg( expr );`
`1187`	`1188`	`}`
`1188`	`1189`	`else if ( type == "geometry" )`
`1189`	`1190`	`{`
`1190`	`1191`	`return QString( "%1(%2)" )`
`1191`	`1192`	`.arg( majorVersion() < 2 ? "asewkt" : "st_asewkt" )`
`1192`		`- .arg( quotedIdentifier( fld.name() ) );`
	`1193`	`+ .arg( expr );`
`1193`	`1194`	`}`
`1194`	`1195`	`else if ( type == "geography" )`
`1195`	`1196`	`{`
`1196`		`- return QString( "st_astext(%1)" ).arg( quotedIdentifier( fld.name() ) );`
	`1197`	`+ return QString( "st_astext(%1)" ).arg( expr );`
`1197`	`1198`	`}`
`1198`	`1199`	`else`
`1199`	`1200`	`{`
`1200`		`- return quotedIdentifier( fld.name() ) + "::text";`
	`1201`	`+ return expr + "::text";`
`1201`	`1202`	`}`
`1202`	`1203`	`}`
`1203`	`1204`