Entity Framework Stored Procedure Discover How to Use SP in LINQ

What is Stored Procedure?

A stored procedure a SQL code that you can save so that the code can be reused over and over again.

• If you have an SQL query that you write over and over again, save it as a stored procedure, and then call it to execute it.
• You can also pass parameters to a stored procedure so that the stored procedure can act based on the parameter value(s) that is passed.

Stored Procedure in Entity Framework

The Entity Framework allows you to use stored procedures in the Entity Data Model.

• You can use stored procedures to perform predefined logic on database tables.
• It can also specify that EF should use your stored procedures for inserting, updating, or deleting entities.

Here is a simple stored procedure, it will return all the records from Authors table when executed.

IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = 
   OBJECT_ID(N'[dbo].[GetAllAuthors]') AND type in (N'P', N'PC'))

BEGIN

   EXEC dbo.sp_executesql @statement = N'
   CREATE PROCEDURE [dbo].[GetAllAuthors]
   AS
   SELECT * FROM dbo.Authors
   '
END

In Entity Framework, you can execute stored procedures using Database.SqlQuery method.

using (var context = new BookStore())
{
    var authors = context.Database
        .SqlQuery<Author>("EXECUTE dbo.GetAllAuthors")
        .ToList();
}

Try it

Passing Parameters

You can also pass parameters when executing stored procedures. The following stored procedure will return a book record based on BookId which is passed as a parameter.

IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = 
   OBJECT_ID(N'[dbo].[GetBookById]') AND type in (N'P', N'PC'))

BEGIN

   EXEC dbo.sp_executesql @statement = N'
   CREATE PROCEDURE [dbo].[GetBookById]
   @BookId int
   AS
   SELECT * FROM dbo.Books 
   WHERE BookId = @BookId
   '
END

When it is executed, It will return a specific book record from Books table based on BookId = 2 passed as a parameter.

using (var context = new BookStore())
{
    var books = context.Database
        .SqlQuery<Book>("EXECUTE dbo.GetBookById 2")
        .ToList();
}

Try it