OGRSpatialReference *OGROCIDataSource::FetchSRS( int nId )
{
if( nId < 0 )
return NULL;
/* -------------------------------------------------------------------- */
/* First, we look through our SRID cache, is it there? */
/* -------------------------------------------------------------------- */
int i;
for( i = 0; i < nKnownSRID; i++ )
{
if( panSRID[i] == nId )
return papoSRS[i];
}
/* -------------------------------------------------------------------- */
/* Try looking up in MDSYS.CS_SRS table. */
/* -------------------------------------------------------------------- */
OGROCIStatement oStatement( GetSession() );
char szSelect[200], **papszResult;
snprintf( szSelect, sizeof(szSelect),
"SELECT WKTEXT, AUTH_SRID, AUTH_NAME FROM MDSYS.CS_SRS "
"WHERE SRID = %d AND WKTEXT IS NOT NULL", nId );
if( oStatement.Execute( szSelect ) != CE_None )
return NULL;
papszResult = oStatement.SimpleFetchRow();
if( CSLCount(papszResult) < 1 )
return NULL;
/* -------------------------------------------------------------------- */
/* Turn into a spatial reference. */
/* -------------------------------------------------------------------- */
char *pszWKT = papszResult[0];
OGRSpatialReference *poSRS = NULL;
poSRS = new OGRSpatialReference();
if( poSRS->importFromWkt( &pszWKT ) != OGRERR_NONE )
{
delete poSRS;
poSRS = NULL;
}
/* -------------------------------------------------------------------- */
/* If we have a corresponding EPSG code for this SRID, use that */
/* authority. */
/* -------------------------------------------------------------------- */
int bGotEPSGMapping = FALSE;
for( i = 0; anEPSGOracleMapping[i] != 0; i += 2 )
{
if( anEPSGOracleMapping[i] == nId )
{
poSRS->SetAuthority( poSRS->GetRoot()->GetValue(), "EPSG",
anEPSGOracleMapping[i+1] );
bGotEPSGMapping = TRUE;
break;
}
}
/* -------------------------------------------------------------------- */
/* Insert authority information, if it is available. */
/* -------------------------------------------------------------------- */
if( papszResult[1] != NULL && atoi(papszResult[1]) != 0
&& papszResult[2] != NULL && strlen(papszResult[1]) != 0
&& poSRS->GetRoot() != NULL
&& !bGotEPSGMapping )
{
poSRS->SetAuthority( poSRS->GetRoot()->GetValue(),
papszResult[2], atoi(papszResult[1]) );
}
/* -------------------------------------------------------------------- */
/* Add to the cache. */
/* -------------------------------------------------------------------- */
panSRID = (int *) CPLRealloc(panSRID,sizeof(int) * (nKnownSRID+1) );
papoSRS = (OGRSpatialReference **)
CPLRealloc(papoSRS, sizeof(void*) * (nKnownSRID + 1) );
panSRID[nKnownSRID] = nId;
papoSRS[nKnownSRID] = poSRS;
nKnownSRID++;
return poSRS;
}
