qgsalgorithmexecutespatialitequery.cpp

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/***************************************************************************
                         qgsalgorithmexecutespatialitequery.cpp
                         ---------------------
    begin                : May 2020
    copyright            : (C) 2020 by Alexander Bruy
    email                : alexander dot bruy at gmail dot com
 ***************************************************************************/
 
/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#include "qgsalgorithmexecutespatialitequery.h"
#include "qgsproviderregistry.h"
#include "qgsprovidermetadata.h"
#include "qgsabstractdatabaseproviderconnection.h"
#include "qgsvectorlayer.h"
 
 
QString QgsExecuteSpatialiteQueryAlgorithm::name() const
{
  return QStringLiteral( "spatialiteexecutesql" );
}
 
QString QgsExecuteSpatialiteQueryAlgorithm::displayName() const
{
  return QObject::tr( "SpatiaLite execute SQL" );
}
 
QStringList QgsExecuteSpatialiteQueryAlgorithm::tags() const
{
  return QObject::tr( "database,sql,spatialite,execute" ).split( ',' );
}
 
QString QgsExecuteSpatialiteQueryAlgorithm::group() const
{
  return QObject::tr( "Database" );
}
 
QString QgsExecuteSpatialiteQueryAlgorithm::groupId() const
{
  return QStringLiteral( "database" );
}
 
QString QgsExecuteSpatialiteQueryAlgorithm::shortHelpString() const
{
  return QObject::tr( "This algorithm executes a SQL command on a SpatiaLite database. The database is determined by an input layer or file." );
}
 
QString QgsExecuteSpatialiteQueryAlgorithm::shortDescription() const
{
  return QObject::tr( "Executes a SQL command on a SpatiaLite database determined by an input layer or file." );
}
 
QgsExecuteSpatialiteQueryAlgorithm *QgsExecuteSpatialiteQueryAlgorithm::createInstance() const
{
  return new QgsExecuteSpatialiteQueryAlgorithm();
}
 
void QgsExecuteSpatialiteQueryAlgorithm::initAlgorithm( const QVariantMap & )
{
  addParameter( new QgsProcessingParameterVectorLayer( QStringLiteral( "DATABASE" ), QObject::tr( "Database layer (or file)" ), QList<int>() << static_cast<int>( Qgis::ProcessingSourceType::Vector ) ) );
  addParameter( new QgsProcessingParameterString( QStringLiteral( "SQL" ), QObject::tr( "SQL query" ), QVariant(), true ) );
}
 
QVariantMap QgsExecuteSpatialiteQueryAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback )
{
  Q_UNUSED( feedback );
  QgsVectorLayer *layer = parameterAsVectorLayer( parameters, QStringLiteral( "DATABASE" ), context );
  QString databaseUri = layer->dataProvider()->dataSourceUri();
  QgsDataSourceUri uri( databaseUri );
  if ( uri.database().isEmpty() )
  {
    if ( databaseUri.contains( QStringLiteral( "|layername" ), Qt::CaseInsensitive ) )
      databaseUri = databaseUri.left( databaseUri.indexOf( QLatin1String( "|layername" ) ) );
    else if ( databaseUri.contains( QStringLiteral( "|layerid" ), Qt::CaseInsensitive ) )
      databaseUri = databaseUri.left( databaseUri.indexOf( QLatin1String( "|layerid" ) ) );
 
    uri = QgsDataSourceUri( QStringLiteral( "dbname='%1'" ).arg( databaseUri ) );
  }
 
  std::unique_ptr<QgsAbstractDatabaseProviderConnection> conn;
  try
  {
    QgsProviderMetadata *md = QgsProviderRegistry::instance()->providerMetadata( QStringLiteral( "spatialite" ) );
    conn.reset( static_cast<QgsAbstractDatabaseProviderConnection *>( md->createConnection( uri.uri(), QVariantMap() ) ) );
  }
  catch ( QgsProviderConnectionException & )
  {
    throw QgsProcessingException( QObject::tr( "Could not connect to %1" ).arg( uri.uri() ) );
  }
 
  const QString sql = parameterAsString( parameters, QStringLiteral( "SQL" ), context ).replace( '\n', ' ' );
  try
  {
    conn->executeSql( sql );
  }
  catch ( QgsProviderConnectionException &ex )
  {
    throw QgsProcessingException( QObject::tr( "Error executing SQL:\n%1" ).arg( ex.what() ) );
  }
 
  return QVariantMap();
}