ogr2ogr.py 文件源码

def LoadGeometry( pszDS, pszSQL, pszLyr, pszWhere):
    poGeom = None

    poDS = ogr.Open( pszDS, False )
    if poDS is None:
        return None

    if pszSQL is not None:
        poLyr = poDS.ExecuteSQL( pszSQL, None, None )
    elif pszLyr is not None:
        poLyr = poDS.GetLayerByName(pszLyr)
    else:
        poLyr = poDS.GetLayer(0)

    if poLyr is None:
        print("Failed to identify source layer from datasource.")
        poDS.Destroy()
        return None

    if pszWhere is not None:
        poLyr.SetAttributeFilter(pszWhere)

    poFeat = poLyr.GetNextFeature()
    while poFeat is not None:
        poSrcGeom = poFeat.GetGeometryRef()
        if poSrcGeom is not None:
            eType = wkbFlatten(poSrcGeom.GetGeometryType())

            if poGeom is None:
                poGeom = ogr.Geometry( ogr.wkbMultiPolygon )

            if eType == ogr.wkbPolygon:
                poGeom.AddGeometry( poSrcGeom )
            elif eType == ogr.wkbMultiPolygon:
                for iGeom in range(poSrcGeom.GetGeometryCount()):
                    poGeom.AddGeometry(poSrcGeom.GetGeometryRef(iGeom) )

            else:
                print("ERROR: Geometry not of polygon type." )
                if pszSQL is not None:
                    poDS.ReleaseResultSet( poLyr )
                poDS.Destroy()
                return None

        poFeat = poLyr.GetNextFeature()

    if pszSQL is not None:
        poDS.ReleaseResultSet( poLyr )
    poDS.Destroy()

    return poGeom