ogrmysqltablelayer.cpp

GIS系统支持库Geospatial Data Abstraction Library代码.GDAL is a translator library for raster geospatial dat

/******************************************************************************
 * $Id: ogrmysqltablelayer.cpp,v 1.4 2005/02/24 21:54:36 fwarmerdam Exp $
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Purpose:  Implements OGRMySQLTableLayer class.
 * Author:   Frank Warmerdam, [e-mail]
 *
 ******************************************************************************
 * Copyright (c) 2004, Frank Warmerdam <[e-mail]>
 *
 * 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.
 ******************************************************************************
 *
 * $Log: ogrmysqltablelayer.cpp,v $
 * Revision 1.4  2005/02/24 21:54:36  fwarmerdam
 * added support for decimal fields.
 *
 * Revision 1.3  2005/02/22 12:54:27  fwarmerdam
 * use OGRLayer base spatial filter support
 *
 * Revision 1.2  2004/10/08 20:50:48  fwarmerdam
 * avoid leak in GetFeatureCount()
 *
 * Revision 1.1  2004/10/07 20:56:15  fwarmerdam
 * New
 *
 */

#include "cpl_conv.h"
#include "cpl_string.h"
#include "ogr_mysql.h"

CPL_CVSID("$Id: ogrmysqltablelayer.cpp,v 1.4 2005/02/24 21:54:36 fwarmerdam Exp $");

/************************************************************************/
/*                         OGRMySQLTableLayer()                         */
/************************************************************************/

OGRMySQLTableLayer::OGRMySQLTableLayer( OGRMySQLDataSource *poDSIn, 
                                  const char * pszTableName,
                                  int bUpdate, int nSRSIdIn )

{
    poDS = poDSIn;

    pszQuery = NULL;
    pszWHERE = CPLStrdup( "" );
    pszQueryStatement = NULL;
    
    bUpdateAccess = bUpdate;

    iNextShapeId = 0;

    nSRSId = nSRSIdIn;

    poFeatureDefn = ReadTableDefinition( pszTableName );
    
    ResetReading();

    bLaunderColumnNames = TRUE;
}

/************************************************************************/
/*                        ~OGRMySQLTableLayer()                         */
/************************************************************************/

OGRMySQLTableLayer::~OGRMySQLTableLayer()

{
    CPLFree( pszQuery );
    CPLFree( pszWHERE );
}

/************************************************************************/
/*                        ReadTableDefinition()                         */
/*                                                                      */
/*      Build a schema from the named table.  Done by querying the      */
/*      catalog.                                                        */
/************************************************************************/

OGRFeatureDefn *OGRMySQLTableLayer::ReadTableDefinition( const char *pszTable )

{
    MYSQL_RES    *hResult;
    char         szCommand[1024];
    
/* -------------------------------------------------------------------- */
/*      Fire off commands to get back the schema of the table.          */
/* -------------------------------------------------------------------- */
    sprintf( szCommand, "DESCRIBE %s", pszTable );
    if( mysql_query( poDS->GetConn(), szCommand ) )
    {
        poDS->ReportError( "DESCRIBE Failed" );
        return FALSE;
    }

    hResult = mysql_store_result( poDS->GetConn() );
    if( hResult == NULL )
    {
        poDS->ReportError( "mysql_store_result() failed on DESCRIBE result." );
        return FALSE;
    }

/* -------------------------------------------------------------------- */
/*      Parse the returned table information.                           */
/* -------------------------------------------------------------------- */
    OGRFeatureDefn *poDefn = new OGRFeatureDefn( pszTable );
    char           **papszRow;

    while( (papszRow = mysql_fetch_row( hResult )) != NULL )
    {
        const char      *pszType;
        OGRFieldDefn    oField( papszRow[0], OFTString);

        pszType = papszRow[1];
        
        if( pszType == NULL )
            continue;

        if( EQUAL(pszType,"varchar") 
            || (strlen(pszType)>3 && EQUAL(pszType+strlen(pszType)-4,"text"))
            || (strlen(pszType)>3 && EQUAL(pszType+strlen(pszType)-4,"blob"))
            || EQUAL(pszType+strlen(pszType)-4,"enum") 
            || EQUAL(pszType+strlen(pszType)-4,"set") )
        {
            oField.SetType( OFTString );
        }
        else if( EQUAL(pszType,"char")  )
        {
            oField.SetType( OFTString );
            /* TODO: need to work out width */
        }
        else if( EQUALN(pszType,"int",3) )
        {
            oField.SetType( OFTInteger );
        }
        else if( EQUAL(pszType,"tinyint") )
        {
            oField.SetType( OFTInteger );
        }
        else if( EQUAL(pszType,"smallint") )
        {
            oField.SetType( OFTInteger );
        }
        else if( EQUAL(pszType,"mediumint") )
        {
            oField.SetType( OFTInteger );
        }
        else if( EQUAL(pszType,"bigint") )
        {
            oField.SetType( OFTInteger );
        }
        else if( EQUALN(pszType,"decimal",7) )
        {
            oField.SetType( OFTReal );
        }
        else if( EQUAL(pszType,"float") )
        {
            oField.SetType( OFTReal );
        }
        else if( EQUAL(pszType,"double") )
        {
            oField.SetType( OFTReal );
        }
        else if( EQUAL(pszType,"decimal") )
        {
            oField.SetType( OFTReal );
        }
        else if( EQUAL(pszType, "date") ) 
        {
            oField.SetType( OFTString );
            oField.SetWidth( 10 );
        }
        else if( EQUAL(pszType, "time") ) 
        {
            oField.SetType( OFTString );
            oField.SetWidth( 10 );
        }
        else if( EQUAL(pszType, "year") ) 
        {
            oField.SetType( OFTString );
            oField.SetWidth( 10 );
        }
        else if( EQUAL(pszType, "datetime") ) 
        {
            oField.SetType( OFTString );
            oField.SetWidth( 20 );
        }

        // Is this an integer primary key field?
        if( !bHasFid && papszRow[3] != NULL && EQUAL(papszRow[3],"PRI") 
            && oField.GetType() == OFTInteger )
        {
            bHasFid = TRUE;
            pszFIDColumn = CPLStrdup(oField.GetNameRef());
            continue;
        }

        poDefn->AddFieldDefn( &oField );
    }

    mysql_free_result( hResult );

/* -------------------------------------------------------------------- */
/*      Till we support geometry, we can safely mark ourselves as       */
/*      wkbNone.  This lets the built GetExtents() produce an           */
/*      optimized response.                                             */
/* -------------------------------------------------------------------- */
    poDefn->SetGeomType( wkbNone );

    return poDefn;
}

/************************************************************************/
/*                          SetSpatialFilter()                          */
/************************************************************************/

void OGRMySQLTableLayer::SetSpatialFilter( OGRGeometry * poGeomIn )

{
    if( !InstallFilter( poGeomIn ) )
        return;

    BuildWhere();

    ResetReading();
}

/************************************************************************/
/*                             BuildWhere()                             */
/*                                                                      */
/*      Build the WHERE statement appropriate to the current set of     */
/*      criteria (spatial and attribute queries).                       */
/************************************************************************/

void OGRMySQLTableLayer::BuildWhere()

{
    CPLFree( pszWHERE );
    pszWHERE = NULL;

    if( pszQuery != NULL )
    {
        pszWHERE = (char *) CPLMalloc(strlen(pszQuery)+20);
        sprintf( pszWHERE, "WHERE %s ", pszQuery );
    }
    else
    {
        pszWHERE = CPLStrdup("");
    }
}

/************************************************************************/
/*                      BuildFullQueryStatement()                       */
/************************************************************************/

void OGRMySQLTableLayer::BuildFullQueryStatement()

{
    if( pszQueryStatement != NULL )
    {
        CPLFree( pszQueryStatement );
        pszQueryStatement = NULL;
    }