SQLServer Spatial: validate the geometries

[danstoica]

Apparently SqlServer2008 doesn't support invalid geometries with spatial filters. The fact one can select invalid geometries but cannot query a table containg such geometries sounds to me as an inconsistency at least. Since Microsoft seems reluctant to address this issue, an workaround is necessary:

1) filter out the invalid geometries. That is, use "STIsValid() AND ST<spatial op>". This is skip the invalid geometries.

2) implement IsValid() custom function. The user can use it in order to find out which geometries are invalid and potentialy will be skipped by the spatial queries.

Syntax: IsValid(<geometry_property>) with a FdoInt32 return result type.

For example, to find out the invalid geometries: Select * from <class> where IsValid(<property>) = 0;