OGRLayer * OGRDataSource::ExecuteSQL( const char *pszStatement,
OGRGeometry *poSpatialFilter,
const char *pszDialect )
{
const char *pszError;
swq_select *psSelectInfo = NULL;
(void) pszDialect;
/* -------------------------------------------------------------------- */
/* Handle CREATE INDEX statements specially. */
/* -------------------------------------------------------------------- */
if( EQUALN(pszStatement,"CREATE INDEX",12) )
{
ProcessSQLCreateIndex( pszStatement );
return NULL;
}
/* -------------------------------------------------------------------- */
/* Handle DROP INDEX statements specially. */
/* -------------------------------------------------------------------- */
if( EQUALN(pszStatement,"DROP INDEX",10) )
{
ProcessSQLDropIndex( pszStatement );
return NULL;
}
/* -------------------------------------------------------------------- */
/* Preparse the SQL statement. */
/* -------------------------------------------------------------------- */
pszError = swq_select_preparse( pszStatement, &psSelectInfo );
if( pszError != NULL )
{
CPLError( CE_Failure, CPLE_AppDefined,
"SQL: %s", pszError );
return NULL;
}
/* -------------------------------------------------------------------- */
/* Validate that all the source tables are recognised, count */
/* fields. */
/* -------------------------------------------------------------------- */
int nFieldCount = 0, iTable;
for( iTable = 0; iTable < psSelectInfo->table_count; iTable++ )
{
swq_table_def *psTableDef = psSelectInfo->table_defs + iTable;
OGRLayer *poSrcLayer;
OGRDataSource *poTableDS = this;
if( psTableDef->data_source != NULL )
{
poTableDS = (OGRDataSource *)
OGROpenShared( psTableDef->data_source, FALSE, NULL );
if( poTableDS == NULL )
{
if( strlen(CPLGetLastErrorMsg()) == 0 )
CPLError( CE_Failure, CPLE_AppDefined,
"Unable to open secondary datasource\n"
"`%s' required by JOIN.",
psTableDef->data_source );
swq_select_free( psSelectInfo );
return NULL;
}
// This drops explicit reference, but leave it open for use by
// code in ogr_gensql.cpp
poTableDS->Dereference();
}
poSrcLayer = poTableDS->GetLayerByName( psTableDef->table_name );
if( poSrcLayer == NULL )
{
CPLError( CE_Failure, CPLE_AppDefined,
"SELECT from table %s failed, no such table/featureclass.",
psTableDef->table_name );
swq_select_free( psSelectInfo );
return NULL;
}
nFieldCount += poSrcLayer->GetLayerDefn()->GetFieldCount();
}
/* -------------------------------------------------------------------- */
/* Build the field list for all indicated tables. */
/* -------------------------------------------------------------------- */
swq_field_list sFieldList;
int nFIDIndex = 0;
memset( &sFieldList, 0, sizeof(sFieldList) );
sFieldList.table_count = psSelectInfo->table_count;
sFieldList.table_defs = psSelectInfo->table_defs;
sFieldList.count = 0;
sFieldList.names = (char **) CPLMalloc( sizeof(char *) * (nFieldCount+1) );
sFieldList.types = (swq_field_type *)
CPLMalloc( sizeof(swq_field_type) * (nFieldCount+1) );
sFieldList.table_ids = (int *)
CPLMalloc( sizeof(int) * (nFieldCount+1) );
sFieldList.ids = (int *)
CPLMalloc( sizeof(int) * (nFieldCount+1) );
for( iTable = 0; iTable < psSelectInfo->table_count; iTable++ )
{
swq_table_def *psTableDef = psSelectInfo->table_defs + iTable;
OGRDataSource *poTableDS = this;
OGRLayer *poSrcLayer;
int iField;
if( psTableDef->data_source != NULL )
{
poTableDS = (OGRDataSource *)
OGROpenShared( psTableDef->data_source, FALSE, NULL );
CPLAssert( poTableDS != NULL );
poTableDS->Dereference();
}
poSrcLayer = poTableDS->GetLayerByName( psTableDef->table_name );
for( iField = 0;
iField < poSrcLayer->GetLayerDefn()->GetFieldCount();
iField++ )
{
OGRFieldDefn *poFDefn=poSrcLayer->GetLayerDefn()->GetFieldDefn(iField);
int iOutField = sFieldList.count++;
sFieldList.names[iOutField] = (char *) poFDefn->GetNameRef();
if( poFDefn->GetType() == OFTInteger )
sFieldList.types[iOutField] = SWQ_INTEGER;
else if( poFDefn->GetType() == OFTReal )
sFieldList.types[iOutField] = SWQ_FLOAT;
else if( poFDefn->GetType() == OFTString )
sFieldList.types[iOutField] = SWQ_STRING;
else
sFieldList.types[iOutField] = SWQ_OTHER;
sFieldList.table_ids[iOutField] = iTable;
sFieldList.ids[iOutField] = iField;
}
if( iTable == 0 )
nFIDIndex = poSrcLayer->GetLayerDefn()->GetFieldCount();
}
/* -------------------------------------------------------------------- */
/* Expand '*' in 'SELECT *' now before we add the pseudo field */
/* 'FID'. */
/* -------------------------------------------------------------------- */
pszError =
swq_select_expand_wildcard( psSelectInfo, &sFieldList );
if( pszError != NULL )
{
CPLError( CE_Failure, CPLE_AppDefined,
"SQL: %s", pszError );
return NULL;
}
sFieldList.names[sFieldList.count] = "FID";
sFieldList.types[sFieldList.count] = SWQ_INTEGER;
sFieldList.table_ids[sFieldList.count] = 0;
sFieldList.ids[sFieldList.count] = nFIDIndex;
sFieldList.count++;
/* -------------------------------------------------------------------- */
/* Finish the parse operation. */
/* -------------------------------------------------------------------- */
pszError = swq_select_parse( psSelectInfo, &sFieldList, 0 );
CPLFree( sFieldList.names );
CPLFree( sFieldList.types );
CPLFree( sFieldList.table_ids );
CPLFree( sFieldList.ids );
if( pszError != NULL )
{
CPLError( CE_Failure, CPLE_AppDefined,
"SQL: %s", pszError );
return NULL;
}
/* -------------------------------------------------------------------- */
/* Everything seems OK, try to instantiate a results layer. */
/* -------------------------------------------------------------------- */
OGRGenSQLResultsLayer *poResults;
poResults = new OGRGenSQLResultsLayer( this, psSelectInfo,
poSpatialFilter );
// Eventually, we should keep track of layers to cleanup.
return poResults;
}
OGRLayer * OGRDataSource::ExecuteSQL( const char *pszStatement,
OGRGeometry *poSpatialFilter,
const char *pszDialect )
{
const char *pszError;
swq_select *psSelectInfo = NULL;
(void) pszDialect;
swq_field_list sFieldList;
int nFIDIndex = 0;
OGRGenSQLResultsLayer *poResults = NULL;
memset( &sFieldList, 0, sizeof(sFieldList) );
/* -------------------------------------------------------------------- */
/* Handle CREATE INDEX statements specially. */
/* -------------------------------------------------------------------- */
if( EQUALN(pszStatement,"CREATE INDEX",12) )
{
ProcessSQLCreateIndex( pszStatement );
return NULL;
}
/* -------------------------------------------------------------------- */
/* Handle DROP INDEX statements specially. */
/* -------------------------------------------------------------------- */
if( EQUALN(pszStatement,"DROP INDEX",10) )
{
ProcessSQLDropIndex( pszStatement );
return NULL;
}
/* -------------------------------------------------------------------- */
/* Preparse the SQL statement. */
/* -------------------------------------------------------------------- */
pszError = swq_select_preparse( pszStatement, &psSelectInfo );
if( pszError != NULL )
{
CPLError( CE_Failure, CPLE_AppDefined,
"SQL: %s", pszError );
return NULL;
}
/* -------------------------------------------------------------------- */
/* Validate that all the source tables are recognised, count */
/* fields. */
/* -------------------------------------------------------------------- */
int nFieldCount = 0, iTable, iField;
int iEDS;
int nExtraDSCount = 0;
OGRDataSource** papoExtraDS = NULL;
OGRSFDriverRegistrar *poReg=OGRSFDriverRegistrar::GetRegistrar();
for( iTable = 0; iTable < psSelectInfo->table_count; iTable++ )
{
swq_table_def *psTableDef = psSelectInfo->table_defs + iTable;
OGRLayer *poSrcLayer;
OGRDataSource *poTableDS = this;
if( psTableDef->data_source != NULL )
{
poTableDS = (OGRDataSource *)
OGROpenShared( psTableDef->data_source, FALSE, NULL );
if( poTableDS == NULL )
{
if( strlen(CPLGetLastErrorMsg()) == 0 )
CPLError( CE_Failure, CPLE_AppDefined,
"Unable to open secondary datasource\n"
"`%s' required by JOIN.",
psTableDef->data_source );
swq_select_free( psSelectInfo );
goto end;
}
/* Keep in an array to release at the end of this function */
papoExtraDS = (OGRDataSource** )CPLRealloc(papoExtraDS,
sizeof(OGRDataSource*) * (nExtraDSCount + 1));
papoExtraDS[nExtraDSCount++] = poTableDS;
}
poSrcLayer = poTableDS->GetLayerByName( psTableDef->table_name );
if( poSrcLayer == NULL )
{
CPLError( CE_Failure, CPLE_AppDefined,
"SELECT from table %s failed, no such table/featureclass.",
psTableDef->table_name );
swq_select_free( psSelectInfo );
goto end;
}
nFieldCount += poSrcLayer->GetLayerDefn()->GetFieldCount();
}
/* -------------------------------------------------------------------- */
/* Build the field list for all indicated tables. */
/* -------------------------------------------------------------------- */
sFieldList.table_count = psSelectInfo->table_count;
sFieldList.table_defs = psSelectInfo->table_defs;
sFieldList.count = 0;
sFieldList.names = (char **) CPLMalloc( sizeof(char *) * (nFieldCount+SPECIAL_FIELD_COUNT) );
sFieldList.types = (swq_field_type *)
CPLMalloc( sizeof(swq_field_type) * (nFieldCount+SPECIAL_FIELD_COUNT) );
sFieldList.table_ids = (int *)
CPLMalloc( sizeof(int) * (nFieldCount+SPECIAL_FIELD_COUNT) );
sFieldList.ids = (int *)
CPLMalloc( sizeof(int) * (nFieldCount+SPECIAL_FIELD_COUNT) );
for( iTable = 0; iTable < psSelectInfo->table_count; iTable++ )
{
swq_table_def *psTableDef = psSelectInfo->table_defs + iTable;
OGRDataSource *poTableDS = this;
OGRLayer *poSrcLayer;
if( psTableDef->data_source != NULL )
{
poTableDS = (OGRDataSource *)
OGROpenShared( psTableDef->data_source, FALSE, NULL );
CPLAssert( poTableDS != NULL );
poTableDS->Dereference();
}
poSrcLayer = poTableDS->GetLayerByName( psTableDef->table_name );
for( iField = 0;
iField < poSrcLayer->GetLayerDefn()->GetFieldCount();
iField++ )
{
OGRFieldDefn *poFDefn=poSrcLayer->GetLayerDefn()->GetFieldDefn(iField);
int iOutField = sFieldList.count++;
sFieldList.names[iOutField] = (char *) poFDefn->GetNameRef();
if( poFDefn->GetType() == OFTInteger )
sFieldList.types[iOutField] = SWQ_INTEGER;
else if( poFDefn->GetType() == OFTReal )
sFieldList.types[iOutField] = SWQ_FLOAT;
else if( poFDefn->GetType() == OFTString )
sFieldList.types[iOutField] = SWQ_STRING;
else
sFieldList.types[iOutField] = SWQ_OTHER;
sFieldList.table_ids[iOutField] = iTable;
sFieldList.ids[iOutField] = iField;
}
if( iTable == 0 )
nFIDIndex = poSrcLayer->GetLayerDefn()->GetFieldCount();
}
/* -------------------------------------------------------------------- */
/* Expand '*' in 'SELECT *' now before we add the pseudo fields */
/* -------------------------------------------------------------------- */
pszError =
swq_select_expand_wildcard( psSelectInfo, &sFieldList );
if( pszError != NULL )
{
swq_select_free( psSelectInfo );
CPLError( CE_Failure, CPLE_AppDefined,
"SQL: %s", pszError );
goto end;
}
for (iField = 0; iField < SPECIAL_FIELD_COUNT; iField++)
{
sFieldList.names[sFieldList.count] = (char*) SpecialFieldNames[iField];
sFieldList.types[sFieldList.count] = SpecialFieldTypes[iField];
sFieldList.table_ids[sFieldList.count] = 0;
sFieldList.ids[sFieldList.count] = nFIDIndex + iField;
sFieldList.count++;
}
/* -------------------------------------------------------------------- */
/* Finish the parse operation. */
/* -------------------------------------------------------------------- */
pszError = swq_select_parse( psSelectInfo, &sFieldList, 0 );
if( pszError != NULL )
{
swq_select_free( psSelectInfo );
CPLError( CE_Failure, CPLE_AppDefined,
"SQL: %s", pszError );
goto end;
}
/* -------------------------------------------------------------------- */
/* Everything seems OK, try to instantiate a results layer. */
/* -------------------------------------------------------------------- */
poResults = new OGRGenSQLResultsLayer( this, psSelectInfo,
poSpatialFilter );
// Eventually, we should keep track of layers to cleanup.
end:
CPLFree( sFieldList.names );
CPLFree( sFieldList.types );
CPLFree( sFieldList.table_ids );
CPLFree( sFieldList.ids );
/* Release the datasets we have opened with OGROpenShared() */
/* It is safe to do that as the 'new OGRGenSQLResultsLayer' itself */
/* has taken a reference on them, which it will release in its */
/* destructor */
for(iEDS = 0; iEDS < nExtraDSCount; iEDS++)
poReg->ReleaseDataSource( papoExtraDS[iEDS] );
CPLFree(papoExtraDS);
return poResults;
}