EF ExecuteStoredCommand with ReturnValue parameter

Question

I'm creating a new application which needs to interface with legacy code :(.

The stored procedure I'm attempting to call uses RETURN for its result. My attempts to execute and consume the return value result in the exception:

InvalidOperationException: When executing a command, parameters must be exclusively database parameters or values.

Changing the stored proc to return the value another way isn't desired, since it either requires updating the legacy app or maintaining a nearly duplicate stored proc.

The legacy stored proc synopsis:

DECLARE @MyID INT
INSERT INTO MyTable ...
SELECT @MyID = IDENTITY()
RETURN @MyID

My Entity Framework / DbContext work, which yields the above InvalidOperationException.

 SqlParameter parm = new SqlParameter() {
    ParameterName = "@MyID",
    Direction = System.Data.ParameterDirection.ReturnValue
 };

 DbContext.Database.ExecuteSqlCommand("EXEC dbo.MyProc", parm);

Looking for any and all solutions which don't require the stored proc to be modified.

Answer 1

You can capture the return value of the stored procedure into an output parameter instead:

SqlParameter parm = new SqlParameter() {  
    ParameterName = "@MyID",  
    SqlDbType = SqlDbType.Int,
    Direction = System.Data.ParameterDirection.Output  
 };  

Database.ExecuteSqlCommand("exec @MyId = dbo.MyProc", parm);

int id = (int)parm.Value;

Answer 2

I know it's a bit late, but this works for me:

var param = new SqlParameter("@Parameter1", txtBoxORsmth.text);

someVariable = ctx.Database.SqlQuery<int>("EXEC dbo.MyProc", param).First();

Answer 3

You don't have to use ExecuteSqlCommand.

You can just get the underlying connection from DbContext.Database.Connection and use raw ADO.NET (CreateCommand(), ExecuteNonQuery(), ...)