问：
I recently migrated from EF Core 2.2 to EF Core 3.0.
Unfortunately, I haven't found a way to call a stored procedure that returns an entity.
In EF Core 2.0 it was possible:
var spParams = new object[] { "bla", "xx" };
var createdPath = ModelContext.Paths.FromSql("AddNodeWithPathProc @p0, @p1", spParams).Single();
In EF Core 3.0 the method FromSQL is replaced with FromSqlRaw. However, I didn't manage to successfully call a stored procedure and then process the value. This is useful when the stored procedure inserts data into the database.
So in EF Core 3.0, I use this code:
var createdPath = ModelContext.Paths.FromSqlRaw("AddNodeWithPathProc @p0, @p1", spParams).Single();
but it will throw an exception, because the generated SQL is invalid and looks something like this:
exec sp_executesql N'SELECT TOP(2) [p].[PathId], [p].[Level], [p].[NodeId], [p].[NodePath], [p].[NodePathString]
FROM (
@sql @p0, @p1
) AS [p]',N'@p0 nvarchar(4000),@p1 nvarchar(4000), @sql nvarchar(100)',@p0=N'1a',@p1=N'', @sql=N'AddNodeWithPathProc'
I tried quite a few variations, but without success.
I'm starting to think that it is not possible to run stored procedures with ModelContext.[IQueryable].FromSqlRaw. In my opinion this kind defeats one of the major reasons for FromSqlRaw because, for normal select statements, LINQ is normally good enough.
Does anyone know how to use stored procedures in combination with FromSqlRaw in EF Core 3.0? Any help is greatly appreciated.
Thanks in advance
PS: I know you can execute a stored procedure with this.Database.ExecuteSqlRaw(SQL, parameters). However, that way it is not possible retrieve any entities that the stored procedure queries.
答：
Try .ToList() instead of .Single(). .Single() is generating the "TOP(2)" wrapper.
var createdPath = ModelContext.Paths.FromSqlRaw("AddNodeWithPathProc {0}, {1}", nodeTitle, parentPathString).ToList();