How to execute SQL queries on LINQ?

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I'm trying to do dml operations on Linq by ExecuteQuery() and ExecuteCommand(). The error that occurred is after execution it doesn't affects the record in database.
For eg: To insert a new record to table in database, I used ExecuteCommand().

After the error occurred i coded with Submitchanges() but there is no result of what i expect.

A Sample code for inserting data to a table:

C#

using(StudentsDbDataContext StudentContext = new StudentsDbDataContext())
{
                int r = StudentContext.ExecuteCommand("insert into tblStudents values ({0},{1},{2})", firstname, lastname, gender);
                if (r > 0) {
                    Console.WriteLine("{0} row added.", r);
                    Console.ReadKey();
                }
            }

What I have tried:

C#

using(StudentsDbDataContext StudentContext = new StudentsDbDataContext())
{
                int r = StudentContext.ExecuteCommand("insert into tblStudents values ({0},{1},{2})", firstname, lastname, gender);
                StudentContext.SubmitChanges();//<--- ADDED
                if (r > 0) {
                    Console.WriteLine("{0} row added.", r);
                    Console.ReadKey();
                }
            }

How to solve this?

Posted 23-Jan-17 4:38am

cgprakash

Updated 23-Jan-17 19:12pm

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Comments

Andy Lanng 23-Jan-17 11:05am

Is this just a really cut down version of your code?
If not then why not use the L2S object insert method?

cgprakash 23-Jan-17 12:27pm

thanks for reply, but i need to do with sql queries using linq methods.

Andy Lanng 23-Jan-17 12:33pm

In that case I think there must be some sort of race condition. Look at the second query: You set r to be the result of the ExecuteCommand, yet it only has a value after you submit changes. There is no await or async style code I can see on your end.
Try adding Thread.Sleep(100); in place of db.SubmitChanges(). If that works then there is some (odd) race condition.

Try writing it like this (pseudo code):
int r;
using (db){
..r = ExecuteCommand("text");
}
if(r>0)
..do stuff

That way you know r will have returned because it must complete the query before disposing of the context.

cgprakash 26-Jan-17 0:34am

i have done it already at the earliest but it doesn't affects.

1 solution

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Gopal Rakhal · Answer 1 · 2017-01-23T19:12:00

Solution 1

Try with below code, may be it help you

C#

StudentContext.Database.SqlQuery<int>("insertProcedure param1 param2 param3");

Posted 23-Jan-17 19:12pm

Gopal Rakhal

Comments

cgprakash 26-Jan-17 0:48am

Thanks for reply Gopal, I didn't get the property "SqlQuery<int>". What to do?

Gopal Rakhal 26-Jan-17 2:00am

It is property of EF.
https://msdn.microsoft.com/en-us/library/jj592907(v=vs.113).aspx