Querying SQL Geometry data using Longitude and Latitude - sql

Question

I have downloaded a shapefile from Ordinance Survey website, and imported it into SQL using ShpToSql.exe, here the setup
This imports fine.
Now i want to query what region a particular longitude and latitude is within.
Using the following
Postcode: WD25 7LR (Harry Potter Studios :D)
Latitude: 51.6910751568794
Longitude: -0.418128358906299
I thought i could write something like
DECLARE #g geography
set #g = geography::Point(51.6910751568794, -0.418128358906299, 4326)
select [name] from region where #g.STWithin(geom) is not null
But that returns an error message of Operand type clash: geometry is incompatible with geography
So i tried to change the data type to geometry, so code looks like this
declare #g geometry
set #g = geometry::Point(51.6910751568794, -0.418128358906299, 4326)
select [name] from region where #g.STWithin(geom) = 1
But no results are returned.
Can someone help me with this please. Just want to know if a longitude and latitude is within a particular POLYGON.
UPDATE:
I have tried to import the .shp file using Geography data type, but this gives an error message when i try to import it
And even if i still try to import it, i them get a message like this for every shape in the shp file

Answer 1

SQL Server will not allow comparisons between geometry and geography data types.
If you are not concerned with being exact, you could perform your original query with the point as a geometry type. This will work reasonably well in most small cases where you aren't comparing odd shapes and across hemispheres.
DECLARE #g geometry
set #g = geometry::Point(51.6910751568794, -0.418128358906299, 4326)
select [name] from region where #g.STWithin(geom) is not null
Otherwise you will need to import the data as a geography type and based on your note there might be some malformed data in the shapefile.