Database.ExecuteSqlCommand（）在执行存储过程时挂起

Question

I am working with a database that I do not have much control over. I am trying to execute a stored procedure using the Database.ExecuteSqlCommand method in a C# Web API call. I have been able to successfully use this method on other stored procedures with no issue. When I try to execute this particular stored procedure, however, the application freezes. I have it in a try catch and it doesn't throw any exceptions. It will just stay in this state indefinitely. I have to go into SSMS and kill the process associated to the call. When I kill the process, the Web API continues. If I do the same EXEC command in SSMS, it works just fine returning a single row set of RETURN_VALUE = 0. I added this RETURN_VALUE = 0 manually at the end of the procedure thinking this might have been part of the issue.

The C# code is:

try
{
    entities.Database.ExecuteSqlCommand("EXEC [dbo].[SPCHANGEORDER]");
    return Ok();
}
catch (Exception e)
{
    Console.WriteLine(e.ToString());
    return Content(HttpStatusCode.BadRequest, "SQL Server Exception");
}

The stored procedure does call some other stored procedures as well as some inserts, updates, and deletes. I know one of the nested stored procedures does several EXEC xp_cmdshell commands as well. I know this isn't a lot to go off of, but I hope someone can help me with a path to at least find the error. Thanks!

EDIT I used SQL Server Profiler and found where it was being executed. I copy/pasted the sets into an SSMS query window, and was still successfully able to execute the stored proc.

Profiler Window

SSMS Query

Answer 1

EF wraps native SQL Command calls in a transaction, by default. Depending on what your stored procedure does, this might be the issue. For instance if your stored procedure makes linked server calls, this could cause it to require a Distributed Transaction.

What I suspect is happening here is the transaction is causing an undetectable deadlock, since your procedure is calling xp_cmdshell. If that external program is trying to read data written by your stored procedure, wrapping it in a transaction would cause that external program to either not see your changes, or block on your uncommitted transaction. (Since your stored proc is using xp_cmdshell to indirectly create a second connection, SQL Server can't detect the deadlock.)

Anyway to disable the transaction try:

entities.Configuration.EnsureTransactionsForFunctionsAndCommands = false;
entities.Database.ExecuteSqlCommand("EXEC [dbo].[SPCHANGEORDER]");