c# - Is it possible to use SqlGeography with Linq to Sql? -


I Microsoft.SqlServer.Types.SqlGeography . I fully understand that Linga's support for SQL is not very good. I have tried several methods, from the beginning, from the beginning ( Geography , CLR type of SqlGeography ) would be the database type. It produces NotSupportedException , which is widely discussed through the blog.

Then, as geography column, verb (maximum) , as geography is a UDT form of binary Is stored in. It works fine (with some binary reading and writing extension methods).

However, now I am running in a very vague problem, which seems to have not happened to many other people.

System.InstallCastcast Exception: Unable to type 'Microsoft.SqlServer.Types.SqlGeography' type 'System.Byte []' to type.

This error is removed from a objectmatizerizer via a query again. This only appears when tables containing geography columns are inserted into a query (such as using the code to insert EntityRef ).

System My question: If I'm retrieving the Geography column as varbinary (max) , then I Reverse error may be expected: Byte [] to SqlGeography can not be inserted. I will understand that I do not let me have SQL classes from partial LINQ which hides binary conversion ... can this be the problem?

Any help is appreciated, and I know that probably is not enough information.

Extra:

  • A Geography column in Visual Studio DBML Designer with 'Server Data Type' = Geography Generates this error: Specified type 'geography' is not a valid provider type.
  • A geography with a 'server data type' in Visual Studio dbml designer generates this error: to execute as SQL The node 'value' could not be formatted.

    • Local type Linq is not supported by SQL I support "Great Is not "- it's not anybody.

    You can read as a blob, but you can not do this by changing the column type from links to sql. You must change your questions at the database level to return the columns using the CAST statement as the varbinary statement. You can do this by adding a computed varbinary column to the table level, so that Linq is happily a byte [] .

    , some DDLs like this: 

      ALTER TABLE FooTable ADD LocationData AS CAST (varbinary (max) as the location)  < / Pre> 
     Then, use the  Delete Location  column from its Linux to the SQL class, and instead  LocationData .  
     If you need access to the actual  SqlGeography  example, you will need to change it in the byte array and change it and change it. 
     
     You can add this process to a bit more "automated" partial Linux by adding up to the SQL unit square and adding an auto-convertible property: 
       public partial class Foo {public SqlGeography location {get {return SqlGeography.STGeomFromWKB (LocationData, 4326); } Set {LocationData = value.STAsBinary (); }}

    It assumes that the location data is the computed varbinary column name; If you do not include the "real" location column in your SQL definition with SQL definition, then you can add it to ad hoc fashion above.

    Also keep in mind that you are able to do more than read and write this column; If you really ask about it (i.e. it's included in a where predicate), you will get the same Not SupportedException .


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