Entity Framework Core, Stored Procedure - entity-framework

Question

I am totally confused regarding how to use Stored Procedures using Entity Framework Core. If the stored procedure return an anonymous type, how do I retrieve the data? If the return type is not anonymous, what should I do? How do I add input/output parameters?
I am asking these questions because everywhere I look, I get a different answer. I guess EF Core is evolving rapidly and Microsoft is dabbling with a lot of ideas.

Answer 1

How do I add input/output parameters?
I'm going to answer this particular question of yours.
Below is a TSQL stored procedure with two input and two output parameters
CREATE PROCEDURE [dbo].[yourstoredprocedure]
-- Add the parameters for the stored procedure here
#varone bigint
,#vartwo Date
,#varthree double precision OUTPUT
,#varfour bigint OUTPUT
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
-- YOUR CODE HERE
SET #varthree = 10.02;
SET #varfour = #varone;
return;
END
Now To execute this stored procedure using Entity Framework Core
MyContext.Database
.ExecuteSqlCommand(#"EXECUTE [yourstoredprocedure] " +
" {0} " +
", {1} " +
",#varthree OUTPUT " +
", #varfour OUTPUT ", dataOne, dataTwo, outputVarOne, outputVarTwo);
var outputResultOne= outputVarOne.Value as double?;
var outputResultTwo= outputVarTwo.Value as long?;
You can pass your input simply using parameterized query as above. You can also create named parameters. such as for output parameters, I've created two named parameters as -
var outputVarOne = new SqlParameter
{
ParameterName = "#varthree ",
DbType = System.Data.DbType.Double,
Direction = System.Data.ParameterDirection.Output
};
var outputVarTwo = new SqlParameter
{
ParameterName = "#varfour ",
DbType = System.Data.DbType.Int64,
Direction = System.Data.ParameterDirection.Output
};
And This is how using EF Core you execute a stored procedure with input and output parameters. Hope this helps someone.

Answer 2

This solution provides methods that call a stored procedure and maps the returned value to a defined (non-model) entity. https://github.com/verdie-g/StoredProcedureDotNetCore
Microsoft address this issue:
"SQL queries can only be used to return entity types that are part of your model. There is an enhancement on our backlog to enable returning ad-hoc types from raw SQL queries." https://learn.microsoft.com/en-us/ef/core/querying/raw-sql
And here is the issue tracked in GitHub: https://github.com/aspnet/EntityFramework/issues/1862

Answer 3

you might use an extention like StoredProcedureEFCore
Then the usage is more intuitively.
List rows = null;
ctx.LoadStoredProc("dbo.ListAll")
.AddParam("limit", 300L)
.AddParam("limitOut", out IOutParam<long> limitOut)
.Exec(r => rows = r.ToList<Model>());
long limitOutValue = limitOut.Value;
ctx.LoadStoredProc("dbo.ReturnBoolean")
.AddParam("boolean_to_return", true)
.ReturnValue(out IOutParam<bool> retParam)
.ExecNonQuery();
bool b = retParam.Value;
ctx.LoadStoredProc("dbo.ListAll")
.AddParam("limit", 1L)
.ExecScalar(out long l);