[mssql] Allow SQL queries as layer sources

src/providers/mssql/CMakeLists.txt

@@ -11,6 +11,7 @@ set(MSSQL_SRCS
   qgsmssqlsqlquerybuilder.cpp
   qgsmssqltransaction.cpp
   qgsmssqldatabase.cpp
+  qgsmssqlutils.cpp
 )
 
 if (WITH_GUI)

src/providers/mssql/qgsmssqlconnection.cpp

@@ -18,6 +18,7 @@
 #include "qgsmssqlconnection.h"
 #include "qgsmssqlprovider.h"
 #include "qgsmssqldatabase.h"
+#include "qgsmssqlutils.h"
 #include "qgslogger.h"
 #include "qgssettings.h"
 #include "qgsdatasourceuri.h"
@@ -422,7 +423,7 @@ QString QgsMssqlConnection::buildQueryForTables( bool allowTablesWithNoGeometry,
   {
     QStringList quotedSchemas;
     for ( const QString &sch : excludedSchemaList )
-      quotedSchemas.append( QgsMssqlProvider::quotedValue( sch ) );
+      quotedSchemas.append( QgsMssqlUtils::quotedValue( sch ) );
     notSelectedSchemas = quotedSchemas.join( ',' );
     notSelectedSchemas.prepend( QStringLiteral( "( " ) );
     notSelectedSchemas.append( QStringLiteral( " )" ) );

src/providers/mssql/qgsmssqldatabase.cpp

@@ -20,6 +20,7 @@
 #include "qgsvariantutils.h"
 #include "qgsmssqlprovider.h"
 #include "qgsdbquerylog.h"
+#include "qgsmssqlutils.h"
 
 #include <QCoreApplication>
 #include <QtDebug>
@@ -165,59 +166,6 @@ QSqlQuery QgsMssqlDatabase::createQuery()
   return QSqlQuery( d );
 }
 
-QMetaType::Type QgsMssqlDatabase::decodeSqlType( const QString &sqlTypeName )
-{
-  QMetaType::Type type = QMetaType::Type::UnknownType;
-  // cloned branches are intentional here for improved readability
-  // NOLINTBEGIN(bugprone-branch-clone)
-  if ( sqlTypeName.startsWith( QLatin1String( "decimal" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "numeric" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "real" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "float" ), Qt::CaseInsensitive ) )
-  {
-    type = QMetaType::Type::Double;
-  }
-  else if ( sqlTypeName.startsWith( QLatin1String( "char" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "nchar" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "varchar" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "nvarchar" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "text" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "ntext" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "uniqueidentifier" ), Qt::CaseInsensitive ) )
-  {
-    type = QMetaType::Type::QString;
-  }
-  else if ( sqlTypeName.startsWith( QLatin1String( "smallint" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "int" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "bit" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "tinyint" ), Qt::CaseInsensitive ) )
-  {
-    type = QMetaType::Type::Int;
-  }
-  else if ( sqlTypeName.startsWith( QLatin1String( "bigint" ), Qt::CaseInsensitive ) )
-  {
-    type = QMetaType::Type::LongLong;
-  }
-  else if ( sqlTypeName.startsWith( QLatin1String( "binary" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "varbinary" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "image" ), Qt::CaseInsensitive ) )
-  {
-    type = QMetaType::Type::QByteArray;
-  }
-  else if ( sqlTypeName.startsWith( QLatin1String( "datetime" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "smalldatetime" ), Qt::CaseInsensitive ) || sqlTypeName.startsWith( QLatin1String( "datetime2" ), Qt::CaseInsensitive ) )
-  {
-    type = QMetaType::Type::QDateTime;
-  }
-  else if ( sqlTypeName.startsWith( QLatin1String( "date" ), Qt::CaseInsensitive ) )
-  {
-    type = QMetaType::Type::QDate;
-  }
-  else if ( sqlTypeName.startsWith( QLatin1String( "timestamp" ), Qt::CaseInsensitive ) )
-  {
-    type = QMetaType::Type::QString;
-  }
-  else if ( sqlTypeName.startsWith( QLatin1String( "time" ), Qt::CaseInsensitive ) )
-  {
-    type = QMetaType::Type::QTime;
-  }
-  else
-  {
-    QgsDebugError( QStringLiteral( "Unknown field type: %1" ).arg( sqlTypeName ) );
-    // Everything else just dumped as a string.
-    type = QMetaType::Type::QString;
-  }
-  // NOLINTEND(bugprone-branch-clone)
-
-  return type;
-}
-
-
 bool QgsMssqlDatabase::loadFields( FieldDetails &details, const QString &schema, const QString &tableName, QString &error )
 {
   error.clear();
@@ -251,7 +199,7 @@ bool QgsMssqlDatabase::loadFields( FieldDetails &details, const QString &schema,
     const QString sql2 { QStringLiteral( "SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS TC"
                                          " INNER JOIN INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE CC ON TC.CONSTRAINT_NAME = CC.CONSTRAINT_NAME"
                                          " WHERE TC.CONSTRAINT_SCHEMA = %1 AND TC.TABLE_NAME = %2 AND TC.CONSTRAINT_TYPE = 'unique'" )
-                           .arg( QgsMssqlProvider::quotedValue( schema ), QgsMssqlProvider::quotedValue( tableName ) ) };
+                           .arg( QgsMssqlUtils::quotedValue( schema ), QgsMssqlUtils::quotedValue( tableName ) ) };
     if ( !LoggedExec( query, sql2 ) )
     {
       error = query.lastError().text();
@@ -264,7 +212,7 @@ bool QgsMssqlDatabase::loadFields( FieldDetails &details, const QString &schema,
     }
   }
 
-  const QString sql3 { QStringLiteral( "exec sp_columns @table_name = %1, @table_owner = %2" ).arg( QgsMssqlProvider::quotedValue( tableName ), QgsMssqlProvider::quotedValue( schema ) ) };
+  const QString sql3 { QStringLiteral( "exec sp_columns @table_name = %1, @table_owner = %2" ).arg( QgsMssqlUtils::quotedValue( tableName ), QgsMssqlUtils::quotedValue( schema ) ) };
   if ( !LoggedExec( query, sql3 ) )
   {
     error = query.lastError().text();
@@ -290,7 +238,6 @@ bool QgsMssqlDatabase::loadFields( FieldDetails &details, const QString &schema,
     }
     else
     {
-      const QMetaType::Type sqlType = decodeSqlType( sqlTypeName );
       if ( sqlTypeName == QLatin1String( "int identity" ) || sqlTypeName == QLatin1String( "bigint identity" ) )
       {
         details.primaryKeyType = PrimaryKeyType::Int;
@@ -303,46 +250,14 @@ bool QgsMssqlDatabase::loadFields( FieldDetails &details, const QString &schema,
         pkCandidates << colName;
       }
 
-      QgsField field;
-      if ( sqlType == QMetaType::Type::QString )
-      {
-        // Field length in chars is column 7 ("Length") of the sp_columns output,
-        // except for uniqueidentifiers which must use column 6 ("Precision").
-        int length = query.value( sqlTypeName.startsWith( QStringLiteral( "uniqueidentifier" ), Qt::CaseInsensitive ) ? 6 : 7 ).toInt();
-        if ( sqlTypeName.startsWith( QLatin1Char( 'n' ) ) )
-        {
-          length = length / 2;
-        }
-        field = QgsField( colName, sqlType, sqlTypeName, length );
-      }
-      else if ( sqlType == QMetaType::Type::Double )
-      {
-        field = QgsField( colName, sqlType, sqlTypeName, query.value( QStringLiteral( "PRECISION" ) ).toInt(), sqlTypeName == QLatin1String( "decimal" ) || sqlTypeName == QLatin1String( "numeric" ) ? query.value( QStringLiteral( "SCALE" ) ).toInt() : -1 );
-      }
-      else if ( sqlType == QMetaType::Type::QDate || sqlType == QMetaType::Type::QDateTime || sqlType == QMetaType::Type::QTime )
-      {
-        field = QgsField( colName, sqlType, sqlTypeName, -1, -1 );
-      }
-      else
-      {
-        field = QgsField( colName, sqlType, sqlTypeName );
-      }
-
-      // Field nullable
+      const int precision = query.value( 6 ).toInt();
+      const int length = query.value( 7 ).toInt();
+      const int scale = query.value( QStringLiteral( "SCALE" ) ).toInt();
       const bool nullable = query.value( QStringLiteral( "NULLABLE" ) ).toBool();
+      const bool unique = setColumnUnique.contains( colName );
+      const bool readOnly = columnIsIdentity;
 
-      // Set constraints
-      QgsFieldConstraints constraints;
-      if ( !nullable )
-        constraints.setConstraint( QgsFieldConstraints::ConstraintNotNull, QgsFieldConstraints::ConstraintOriginProvider );
-      if ( setColumnUnique.contains( colName ) )
-        constraints.setConstraint( QgsFieldConstraints::ConstraintUnique, QgsFieldConstraints::ConstraintOriginProvider );
-      field.setConstraints( constraints );
-
-      if ( columnIsIdentity )
-      {
-        field.setReadOnly( true );
-      }
+      const QgsField field = QgsMssqlUtils::createField( colName, sqlTypeName, length, precision, scale, nullable, unique, readOnly );
 
       details.attributeFields.append( field );
 
@@ -367,7 +282,7 @@ bool QgsMssqlDatabase::loadFields( FieldDetails &details, const QString &schema,
   {
     query.clear();
     query.setForwardOnly( true );
-    const QString sql4 { QStringLiteral( "exec sp_pkeys @table_name = %1, @table_owner = %2 " ).arg( QgsMssqlProvider::quotedValue( tableName ), QgsMssqlProvider::quotedValue( schema ) ) };
+    const QString sql4 { QStringLiteral( "exec sp_pkeys @table_name = %1, @table_owner = %2 " ).arg( QgsMssqlUtils::quotedValue( tableName ), QgsMssqlUtils::quotedValue( schema ) ) };
     if ( !LoggedExec( query, sql4 ) )
     {
       QgsDebugError( QStringLiteral( "SQL:%1\n  Error:%2" ).arg( query.lastQuery(), query.lastError().text() ) );
@@ -429,6 +344,79 @@ bool QgsMssqlDatabase::loadFields( FieldDetails &details, const QString &schema,
   return true;
 }
 
+bool QgsMssqlDatabase::loadQueryFields( FieldDetails &details, const QString &query, QString &error )
+{
+  error.clear();
+
+  details.attributeFields.clear();
+  details.defaultValues.clear();
+  details.computedColumns.clear();
+
+  // get field spec
+  QSqlQuery dbQuery = createQuery();
+  dbQuery.setForwardOnly( true );
+
+  // TODO SQL server >= 2012 only!
+
+  const QString sql { QStringLiteral( R"raw(
+    EXEC sp_describe_first_result_set
+      %1
+    )raw" )
+                        .arg( QgsMssqlUtils::quotedValue( query ) ) };
+  if ( !LoggedExec( dbQuery, sql ) )
+  {
+    error = dbQuery.lastError().text();
+    return false;
+  }
+
+  int fieldIndex = 0;
+  while ( dbQuery.next() )
+  {
+    fieldIndex++;
+
+    // consider all columns as computed
+    // NOTE: for some queries some fields are updateable. We can determine this through the "is_updateable" column in sp_describe_first_result_set
+    // However the provider has no way to selectively say some columns are updateable but not others, so we treat all queries as completely read-only
+    const int columnOrdinal = dbQuery.value( 1 ).toInt();
+    if ( columnOrdinal != fieldIndex )
+    {
+      QgsDebugError( QStringLiteral( "sp_describe_first_result_set returned out of order results!" ) );
+    }
+
+    const bool isHidden = dbQuery.value( 0 ).toInt();
+    if ( isHidden )
+      continue;
+
+    QString name = dbQuery.value( 2 ).toString();
+    if ( name.isEmpty() )
+      name = QStringLiteral( "col%1" ).arg( fieldIndex );
+
+    const bool isNullable = dbQuery.value( 3 ).toInt();
+    const QString systemTypeName = dbQuery.value( 5 ).toString();
+    const int maxLength = dbQuery.value( 6 ).toInt();
+    const int precision = dbQuery.value( 7 ).toInt();
+    const int scale = dbQuery.value( 8 ).toInt();
+
+
+    // if we don't have an explicitly set geometry column name, and this is a geometry column, then use it
+    // but if we DO have an explicitly set geometry column name, then load the other information if this is that column
+    if ( ( details.geometryColumnName.isEmpty() && ( systemTypeName == QLatin1String( "geometry" ) || systemTypeName == QLatin1String( "geography" ) ) )
+         || name == details.geometryColumnName )
+    {
+      details.geometryColumnName = name;
+      details.geometryColumnType = systemTypeName;
+      details.isGeography = systemTypeName == QLatin1String( "geography" );
+    }
+    else
+    {
+      const QgsField field = QgsMssqlUtils::createField( name, systemTypeName, maxLength, precision, scale, isNullable, false, true );
+      details.attributeFields.append( field );
+    }
+  }
+
+  return true;
+}
+
 
 // -------------------
 

src/providers/mssql/qgsmssqldatabase.h

@@ -81,8 +81,6 @@ class QgsMssqlDatabase
 
     QSqlQuery createQuery();
 
-    static QMetaType::Type decodeSqlType( const QString &sqlTypeName );
-
     struct FieldDetails
     {
         QgsFields attributeFields;
@@ -95,8 +93,16 @@ class QgsMssqlDatabase
         QList<int> primaryKeyAttrs;
     };
 
+    /**
+     * Loads the field details  corresponding to the specified \a schema and \a tableName.
+     */
     bool loadFields( FieldDetails &details, const QString &schema, const QString &tableName, QString &error );
 
+    /**
+     * Loads the field details corresponding to the specified SQL \a query.
+     */
+    bool loadQueryFields( FieldDetails &details, const QString &query, QString &error );
+
   private:
     QgsMssqlDatabase( const QSqlDatabase &db, const QgsDataSourceUri &uri, bool transaction );
 

src/providers/mssql/qgsmssqldataitems.cpp

@@ -19,7 +19,7 @@
 #include "moc_qgsmssqldataitems.cpp"
 #include "qgsmssqlconnection.h"
 #include "qgsmssqldatabase.h"
-
+#include "qgsmssqlutils.h"
 #include "qgsmssqlgeomcolumntypethread.h"
 #include "qgslogger.h"
 #include "qgsmimedatautils.h"
@@ -357,7 +357,7 @@ void QgsMssqlConnectionItem::setLayerType( QgsMssqlLayerProperty layerProperty )
 
   for ( int i = 0; i < typeList.size(); i++ )
   {
-    Qgis::WkbType wkbType = QgsMssqlTableModel::wkbTypeFromMssql( typeList[i] );
+    Qgis::WkbType wkbType = QgsMssqlUtils::wkbTypeFromGeometryType( typeList[i] );
     if ( wkbType == Qgis::WkbType::Unknown )
     {
       QgsDebugError( QStringLiteral( "unsupported geometry type:%1" ).arg( typeList[i] ) );
@@ -512,7 +512,7 @@ QString QgsMssqlLayerItem::createUri()
   QgsDataSourceUri uri = QgsDataSourceUri( connItem->connInfo() );
   uri.setDataSource( mLayerProperty.schemaName, mLayerProperty.tableName, mLayerProperty.geometryColName, mLayerProperty.sql, pkColName );
   uri.setSrid( mLayerProperty.srid );
-  uri.setWkbType( QgsMssqlTableModel::wkbTypeFromMssql( mLayerProperty.type ) );
+  uri.setWkbType( QgsMssqlUtils::wkbTypeFromGeometryType( mLayerProperty.type ) );
   uri.setUseEstimatedMetadata( QgsMssqlConnection::useEstimatedMetadata( connItem->name() ) );
   mDisableInvalidGeometryHandling = QgsMssqlConnection::isInvalidGeometryHandlingDisabled( connItem->name() );
   uri.setParam( QStringLiteral( "disableInvalidGeometryHandling" ), mDisableInvalidGeometryHandling ? QStringLiteral( "1" ) : QStringLiteral( "0" ) );
@@ -560,7 +560,7 @@ void QgsMssqlSchemaItem::addLayers( QgsDataItem *newLayers )
 
 QgsMssqlLayerItem *QgsMssqlSchemaItem::addLayer( const QgsMssqlLayerProperty &layerProperty, bool refresh )
 {
-  Qgis::WkbType wkbType = QgsMssqlTableModel::wkbTypeFromMssql( layerProperty.type );
+  Qgis::WkbType wkbType = QgsMssqlUtils::wkbTypeFromGeometryType( layerProperty.type );
   QString tip = tr( "%1 as %2 in %3" ).arg( layerProperty.geometryColName, QgsWkbTypes::displayString( wkbType ), layerProperty.srid );
 
   Qgis::BrowserLayerType layerType;