EGwsStatus GwsCommonFdoUtils::DescribeSC (
FdoIConnection * conn,
FdoString * scname,
GwsSpatialContextDescription & scdesc
)
{
FdoPtr<FdoIGetSpatialContexts> cmd;
FdoPtr<FdoISpatialContextReader> reader;
scdesc.SetClassName (GWSQualifiedName ());
scdesc.SetPropertyName (NULL);
scdesc.SetSpatialContextName (NULL);
scdesc.SetSpatialContextDesc (NULL);
scdesc.SetCsNameWkt (NULL);
if (scname == NULL || * scname == 0)
return eGwsOk;
try {
cmd = (FdoIGetSpatialContexts *) conn->CreateCommand (FdoCommandType_GetSpatialContexts);
reader = cmd->Execute ();
while (reader->ReadNext ()) {
if (wcscmp (reader->GetName (), scname) == 0) {
FdoString * cswkt = reader->GetCoordinateSystemWkt ();
FdoString * desc = reader->GetDescription ();
double xytol = reader->GetXYTolerance();
scdesc.SetCsNameWkt (cswkt);
scdesc.SetSpatialContextDesc (desc);
scdesc.SetSpatialContextName (scname);
scdesc.SetXYTolerance(xytol);
FdoPtr<FdoByteArray> pByteArray = reader->GetExtent();
if (pByteArray) {
FdoPtr<FdoFgfGeometryFactory> pAwkbFactory = FdoFgfGeometryFactory::GetInstance();
FdoPtr<FdoIGeometry> pGeometry = pAwkbFactory->CreateGeometryFromFgf(pByteArray);
FdoPtr<FdoIEnvelope> pEnvelope = pGeometry->GetEnvelope();
scdesc.SetExtents (pEnvelope);
}
return eGwsOk;
}
}
return eGwsSCNotFound;
} catch (FdoException * fdoEx) {
fdoEx->Release ();
}
// in case when exception thrown, assume that sc are not
// supported.
return eGwsNotSupported;
}
void FdoRdbmsMySqlFilterProcessor::ProcessSpatialCondition (FdoSpatialCondition &filter)
{
//TODO: This function's implementation is a temporary one used by the MySql demo. It must be replaced
// by a proper implementation when full spatial support is added to the MySql provider.
//
// However, the following illustrates a problem that was encountered. Spatial query result sets become
// unreliable ( sometimes they work and sometimes they return no rows when there should be some ) when
// the spatial area coordinates contain fractional parts. This is currently worked around by casting
// these coordinates to long.
DbiConnection *mDbiConnection = mFdoConnection->GetDbiConnection();
const FdoSmLpClassDefinition *classDefinition = mDbiConnection->GetSchemaUtil()->GetClass(mCurrentClassName);
if (classDefinition == NULL || classDefinition->GetClassType() != FdoClassType_FeatureClass)
throw FdoFilterException::Create(NlsMsgGet(FDORDBMS_230, "Spatial condition can only be used with feature classes"));
const FdoSmLpGeometricPropertyDefinition* geomProp =
GetGeometricProperty(classDefinition,
FdoPtr<FdoIdentifier>(filter.GetPropertyName())->GetName());
const FdoString* classTableName = classDefinition->GetDbObjectName();
const FdoString* tableName = geomProp ? geomProp->GetContainingDbObjectName() : L""; // The geometry table name
FdoStringP columnName = GetGeometryColumnNameForProperty(geomProp, true);
FdoStringP columnName2 = GetGeometryColumnNameForProperty(geomProp, false);
FdoStringP spatialClause;
FdoPtr<FdoGeometryValue> geom = dynamic_cast<FdoGeometryValue*>(filter.GetGeometry());
FdoPtr<FdoFgfGeometryFactory> gf;
FdoPtr<FdoByteArray> geomFgf;
FdoPtr<FdoIGeometry> geometryObj;
geomFgf = geom->GetGeometry();
if (geomFgf == NULL)
throw FdoFilterException::Create(NlsMsgGet(FDORDBMS_46, "No geometry value"));
// Geometry factory
gf = FdoFgfGeometryFactory::GetInstance();
geometryObj = gf->CreateGeometryFromFgf(geomFgf);
FdoPtr<FdoIEnvelope> env = geometryObj->GetEnvelope();
double minx = env->GetMinX();
double miny = env->GetMinY();
double maxx = env->GetMaxX();
double maxy = env->GetMaxY();
wchar_t minxStr[NUMBER_FORMAT_SIZE];
wchar_t minyStr[NUMBER_FORMAT_SIZE];
wchar_t maxxStr[NUMBER_FORMAT_SIZE];
wchar_t maxyStr[NUMBER_FORMAT_SIZE];
FdoCommonStringUtil::FormatDouble(minx, minxStr, NUMBER_FORMAT_SIZE);
FdoCommonStringUtil::FormatDouble(miny, minyStr, NUMBER_FORMAT_SIZE);
FdoCommonStringUtil::FormatDouble(maxx, maxxStr, NUMBER_FORMAT_SIZE);
FdoCommonStringUtil::FormatDouble(maxy, maxyStr, NUMBER_FORMAT_SIZE);
// In MySQL 5.0, there really is no secondary filter -- the MBR family of functions
// give the same results as the non-MBR functions, and often aren't even as selective
// as advertised. Plus, some clients pass in geometry conditions with extra dimensions.
// For now, we'll take advantage of MySQL's limitations and reduce all geometry types
// and dimensionalities to a 2D polygon with one ring, and just use the MBRIntersects operator.
FdoStringP buf = FdoStringP::Format(L"MBRIntersects(GeomFromText('Polygon((%ls %ls,%ls %ls,%ls %ls,%ls %ls,%ls %ls))'),\"%ls\")",
minxStr, minyStr,
maxxStr, minyStr,
maxxStr, maxyStr,
minxStr, maxyStr,
minxStr, minyStr,
(FdoString*) columnName);
AppendString((const wchar_t*)buf);
}