Convert sql query to entity framework sql

Question

I need to manage hierarchy data storing in my database. But now I am facing a problem. I am using entity sql for my asp.net. So now, how can I convert those sql to entity query? Here is the SQL query I suppose converts to entity framework query

      WITH RPL ( P_TASK_ID, C_TASK_ID,taskSeq) AS
     (  SELECT  root.P_TASK_ID, root.C_TASK_ID ,root.Seq
        FROM [COMMON.TASK_REL_test] as root
      UNION ALL
        SELECT  child.P_TASK_ID, child.C_TASK_ID, child.Seq
        FROM [COMMON.TASK_REL_test] parent, [COMMON.TASK_REL_test] child
        WHERE  parent.C_TASK_ID = CHILD.P_TASK_ID
     )
SELECT DISTINCT P_TASK_ID, C_TASK_ID,taskSeq
 FROM RPL
  ORDER BY  P_TASK_ID, C_TASK_ID,taskSeq; 

Here is my table structure

   pID  CID   Seq
   NULL 1   1
    1   2   1
    1   3   2
    1   4   3
    2   5   1
    2   6   2
    3   7   1

Here is my insert table query

INSERT into [COMMON.TASK_REL_test](P_TASK_ID,C_TASK_ID, Seq)
values (null,1,1)


INSERT into [COMMON.TASK_REL_test](P_TASK_ID,C_TASK_ID,Seq)
values (1,2,1)


INSERT into [COMMON.TASK_REL_test](P_TASK_ID,C_TASK_ID,Seq)
values (1,4,3)


INSERT into [COMMON.TASK_REL_test](P_TASK_ID,C_TASK_ID,Seq)
values (1,3,2)


INSERT into [COMMON.TASK_REL_test](P_TASK_ID,C_TASK_ID,Seq)
values (2,6,2)

INSERT into [COMMON.TASK_REL_test](P_TASK_ID,C_TASK_ID,Seq)
values (2,5,1)

INSERT into [COMMON.TASK_REL_test](P_TASK_ID,C_TASK_ID,Seq)
values (3,7,1)

Here is my coding

 private void createGridView()
        {
            try
            {


                using (ObjectContext ctx = new ObjectContext(gbcDbConnection.eObjqueryConnection))
                {
                    string result = @"
                                ;WITH RPL ( P_TASK_ID, C_TASK_ID,taskSeq) AS
                                (  SELECT  root.P_TASK_ID, root.C_TASK_ID ,root.Seq
                                   FROM LEWREDBEntities.[COMMON_TASK_REL_test] as root
                         UNION ALL
                                SELECT  child.P_TASK_ID, child.C_TASK_ID, child.Seq
                                 FROM LEWREDBEntities.[COMMON_TASK_REL_test] as parent, LEWREDBEntities.[COMMON_TASK_REL_test] as child
                        WHERE  parent.C_TASK_ID = CHILD.P_TASK_ID
                    )
                         SELECT DISTINCT P_TASK_ID, C_TASK_ID,taskSeq
                         FROM RPL
                         ORDER BY  P_TASK_ID, C_TASK_ID,taskSeq";
                    ObjectQuery<DbDataRecord> query = ctx.CreateQuery<DbDataRecord>(result);
                    string cde = query.ToTraceString();
                }
            }
            catch (Exception ex)
            {
                throw new ApplicationException(ex.Message);
            }

        }

But I am getting an error now.
The query syntax is not valid. Near term ';', line 2, column 34..
Please help.

Answer 1

Missing ;

string result = " ; WITH RPL

edit

Well, ok, I googled a bit and the problem is CreateQuery uses EntitySql syntax, not T-SQL, so here the problem.

You can use ExecuteStoreQuery method:

string result = @" ... "

 var query = ctx.ExecuteStoreQuery<Result>(result);

Where result is a class mapped to the projected columns:

public class Result
{
  public int P_TASK_ID {get; set;}
  ....
}

Answer 2

You are missing ; at the start. And why are you += the string. You can just do like this:

string result=@"
                ;WITH RPL ( P_TASK_ID, C_TASK_ID,taskSeq) AS
                    (  SELECT  root.P_TASK_ID, root.C_TASK_ID ,root.Seq
                        FROM [COMMON.TASK_REL_test] as root
                    UNION ALL
                        SELECT  child.P_TASK_ID, child.C_TASK_ID, child.Seq
                        FROM [COMMON.TASK_REL_test] parent, [COMMON.TASK_REL_test] child
                        WHERE  parent.C_TASK_ID = CHILD.P_TASK_ID
                    )
                SELECT DISTINCT P_TASK_ID, C_TASK_ID,taskSeq
                FROM RPL
                ORDER BY  P_TASK_ID, C_TASK_ID,taskSeq";

Use the @" sign. Easier to read.

Answer 3

If you'll have problems in future in can use Linker. This app can convert sql to linq code due to model. In fact while analysing very difficalt query i realised that it's impossible to full control output t-sql but anyway it was extremly helpfull