ogridbtablelayer.cpp

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/******************************************************************************
 * $Id: ogridbtablelayer.cpp 10646 2007-01-18 02:38:10Z warmerdam $
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  Implements OGRIDBTableLayer class, access to an existing table
 *           (based on ODBC and PG drivers).
 * Author:   Oleg Semykin, [e-mail]
 *
 ******************************************************************************
 * Copyright (c) 2006, Oleg Semykin
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ****************************************************************************/

#include "cpl_conv.h"
#include "cpl_string.h"
#include "ogr_idb.h"

CPL_CVSID("$Id: ogridbtablelayer.cpp 10646 2007-01-18 02:38:10Z warmerdam $");
/************************************************************************/
/*                          OGRIDBTableLayer()                         */
/************************************************************************/

OGRIDBTableLayer::OGRIDBTableLayer( OGRIDBDataSource *poDSIn )

{
    poDS = poDSIn;

    pszQuery = NULL;

    bUpdateAccess = TRUE;
    bHaveSpatialExtents = FALSE;

    iNextShapeId = 0;

    poFeatureDefn = NULL;
}

/************************************************************************/
/*                          ~OGRIDBTableLayer()                          */
/************************************************************************/

OGRIDBTableLayer::~OGRIDBTableLayer()

{
    CPLFree( pszQuery );
    ClearQuery();
}

/************************************************************************/
/*                             Initialize()                             */
/************************************************************************/

CPLErr OGRIDBTableLayer::Initialize( const char *pszTableName,
                                     const char *pszGeomCol,
                                     int bUpdate )

{
    bUpdateAccess = bUpdate;

    ITConnection *poConn = poDS->GetConnection();

    if ( pszFIDColumn )
    {
        CPLFree( pszFIDColumn );
        pszFIDColumn = NULL;
    }

/* -------------------------------------------------------------------- */
/*      Do we have a simple primary key?                                */
/* -------------------------------------------------------------------- */
    if ( pszFIDColumn == NULL )
    {
        ITCursor oGetKey( *poConn );

        CPLString osSql =
                " select sc.colname"
                " from syscolumns sc, sysindexes si, systables st"
                " where st.tabid = si.tabid"
                " and st.tabid = sc.tabid"
                " and si.idxtype = 'U'"
                " and sc.colno = si.part1"
                " and si.part2 = 0" // only one-column keys
                " and st.tabname='";
        osSql += pszTableName;
        osSql += "'";

        if( oGetKey.Prepare( osSql.c_str() ) &&
            oGetKey.Open(ITCursor::ReadOnly) )
        {
            ITValue * poVal = oGetKey.Fetch();
            if ( poVal && poVal->IsNull() == false )
            {
                pszFIDColumn = CPLStrdup(poVal->Printable());
                poVal->Release();
            }

            if( oGetKey.Fetch() ) // more than one field in key!
            {
                CPLFree( pszFIDColumn );
                pszFIDColumn = NULL;

                CPLDebug("OGR_IDB", "Table %s has multiple primary key fields,"
                         " ignoring them all.", pszTableName );
            }
        }
    }

/* -------------------------------------------------------------------- */
/*      Have we been provided a geometry column?                        */
/* -------------------------------------------------------------------- */
    CPLFree( pszGeomColumn );
    if( pszGeomCol == NULL )
        pszGeomColumn = NULL;
    else
        pszGeomColumn = CPLStrdup( pszGeomCol );

/* -------------------------------------------------------------------- */
/*      Get the column definitions for this table.                      */
/* -------------------------------------------------------------------- */
    ITCursor oGetCol( *poConn );
    CPLErr eErr;

    CPLString sql;
    sql.Printf( "select * from %s where 1=0", pszTableName );
    if( ! oGetCol.Prepare( sql.c_str() ) ||
        ! oGetCol.Open(ITCursor::ReadOnly) )
        return CE_Failure;

    eErr = BuildFeatureDefn( pszTableName, &oGetCol );
    if( eErr != CE_None )
        return eErr;

    if( poFeatureDefn->GetFieldCount() == 0 )
    {
        CPLError( CE_Failure, CPLE_AppDefined, 
                  "No column definitions found for table '%s', layer not usable.", 
                  pszTableName );
        return CE_Failure;
    }

/* -------------------------------------------------------------------- */
/*      Do we have XMIN, YMIN, XMAX, YMAX extent fields?                */
/* -------------------------------------------------------------------- */
    if( poFeatureDefn->GetFieldIndex( "XMIN" ) != -1 
        && poFeatureDefn->GetFieldIndex( "XMAX" ) != -1 
        && poFeatureDefn->GetFieldIndex( "YMIN" ) != -1 
        && poFeatureDefn->GetFieldIndex( "YMAX" ) != -1 )
    {
        bHaveSpatialExtents = TRUE;
        CPLDebug( "OGR_IDB", "Table %s has geometry extent fields.",
                  pszTableName );
    }

/* -------------------------------------------------------------------- */
/*      If we got a geometry column, does it exist?  Is it binary?      */
/* -------------------------------------------------------------------- */
    if( pszGeomColumn != NULL )
    {
        int iColumn = oGetCol.RowType()->ColumnId( pszGeomColumn );
        if( iColumn < 0 )
        {
            CPLError( CE_Failure, CPLE_AppDefined, 
                      "Column %s requested for geometry, but it does not exist.", 
                      pszGeomColumn );
            CPLFree( pszGeomColumn );
            pszGeomColumn = NULL;
        }
        bGeomColumnWKB = TRUE;
        /*else
        {
            if( ITCursor::GetTypeMapping(
                    oGetCol.GetColType( iColumn )) == SQL_C_BINARY )
                bGeomColumnWKB = TRUE;
        }*/
    }


    return CE_None;
}

/************************************************************************/
/*                           ClearQuery()                           */
/************************************************************************/

void OGRIDBTableLayer::ClearQuery()

{
    if( poCurr != NULL )
    {
        poCurr->Close();
        delete poCurr;
        poCurr = NULL;
    }
}

/************************************************************************/
/*                            GetQuery()                            */
/************************************************************************/

ITCursor *OGRIDBTableLayer::GetQuery()

{
    if( poCurr == NULL )
        ResetQuery();

    return poCurr;
}

/************************************************************************/
/*                           ResetQuery()                           */
/************************************************************************/

OGRErr OGRIDBTableLayer::ResetQuery()

{
    ClearQuery();

    iNextShapeId = 0;

    poCurr = new ITCursor( *poDS->GetConnection() );

    // Create list of fields
    CPLString osFields;

    if ( pszGeomColumn )
    {
        if ( ! osFields.empty() )
            osFields += ",";

        osFields += "st_asbinary(";
        osFields += pszGeomColumn;
        osFields += ") as ";
        osFields += pszGeomColumn;
    }

    for( int i = 0; i < poFeatureDefn->GetFieldCount(); i++ )
    {
        if ( ! osFields.empty() )
            osFields += ",";

        osFields += poFeatureDefn->GetFieldDefn(i)->GetNameRef();
    }

    CPLString sql;

    sql += "SELECT ";
    sql += osFields;
    sql += " FROM ";
    sql += poFeatureDefn->GetName();

    /* Append attribute query if we have it */
    if( pszQuery != NULL )
    {
        sql += " WHERE ";
        sql += pszQuery;
    }

    /* If we have a spatial filter, and per record extents, query on it */
    if( m_poFilterGeom != NULL && bHaveSpatialExtents )
    {
        if( pszQuery == NULL )
            sql += " WHERE";
        else
            sql += " AND";

        sql.Printf( "%s XMAX > %.8f AND XMIN < %.8f"
                    " AND YMAX > %.8f AND YMIN < %.8f",
                    sql.c_str(),
                    m_sFilterEnvelope.MinX, m_sFilterEnvelope.MaxX,
                    m_sFilterEnvelope.MinY, m_sFilterEnvelope.MaxY );
    }

    CPLDebug( "OGR_IDB", "Exec(%s)", sql.c_str() );
    if( poCurr->Prepare( sql.c_str() ) &&
        poCurr->Open(ITCursor::ReadOnly) )
    {
        return OGRERR_NONE;
    }
    else
    {
        delete poCurr;
        poCurr = NULL;
        return OGRERR_FAILURE;
    }
}

/************************************************************************/
/*                            ResetReading()                            */
/************************************************************************/

void OGRIDBTableLayer::ResetReading()

{
    ClearQuery();
    OGRIDBLayer::ResetReading();
}

/************************************************************************/
/*                             GetFeature()                             */
/************************************************************************/

OGRFeature *OGRIDBTableLayer::GetFeature( long nFeatureId )

{
    if( pszFIDColumn == NULL )
        return OGRIDBLayer::GetFeature( nFeatureId );

    ClearQuery();

    iNextShapeId = nFeatureId;

    poCurr = new ITCursor( *poDS->GetConnection() );

    // Create list of fields
    CPLString osFields;

    if ( poFeatureDefn->GetFieldIndex( pszFIDColumn ) == -1 )
        osFields += pszFIDColumn;

    if ( pszGeomColumn )
    {
        if ( ! osFields.empty() )
            osFields += ",";

        osFields += "st_asbinary(";
        osFields += pszGeomColumn;
        osFields += ") as ";
        osFields += pszGeomColumn;
    }

    for( int i = 0; i < poFeatureDefn->GetFieldCount(); i++ )
    {
        if ( ! osFields.empty() )
            osFields += ",";