Question

I have an SQL query that I have written using CTE. Now, I am moving the repository to use Entity Framework 5.

I am at a loss as to how to integrate (or rewrite) the CTE-based query using Entity Framework 5.

I am using POCO entities with the EF5 and have a bunch of Map classes. There is no EDMX file etc.

I feel like a total noob right now and would appreciate any help pointing me in the right direction.

The CTE query is as following

WITH CDE AS
(
    SELECT * FROM collaboration.Workspace AS W WHERE W.Id = @WorkspaceId
    UNION ALL
    SELECT W.* FROM collaboration.Workspace AS W INNER JOIN CDE ON W.ParentId = CDE.Id AND W.ParentId <> '00000000-0000-0000-0000-000000000000'
)
SELECT
    W.Id AS Id,
    W.Name AS Name,
    W.Description AS Description,
    MAX(WH.ActionedTimeUtc) AS LastUpdatedTimeUtc,
    WH.ActorId AS LastUpdateUserId
FROM
    collaboration.Workspace AS W
    INNER JOIN
    collaboration.WorkspaceHistory AS WH ON W.Id = WH.WorkspaceId
    INNER JOIN
    (
        SELECT TOP 10
            CDE.Id
        FROM
            CDE
            INNER JOIN
            collaboration.WorkspaceHistory AS WH ON WH.WorkspaceId = CDE.Id
        WHERE
            CDE.Id <> @WorkspaceId
        GROUP BY
            CDE.Id,
            CDE.ParentId,
            WH.ActorId,
            WH.Action
        HAVING
            WH.ActorId = @UserId
            AND
            WH.Action <> 4
        ORDER BY
            COUNT(*) DESC
    ) AS Q ON Q.Id = WH.WorkspaceId
GROUP BY
    W.Id,
    W.Name,
    W.Description,
    WH.ActorId
HAVING
    WH.ActorId = @UserId

Answer 1

You must create stored procedure for your SQL query (or use that query directly) and execute it through dbContext.Database.SqlQuery. You are using code-first approach where you don’t have any other options. In EDMX you could use mapped table valued function but code-first doesn’t have such option yet.