Question

I am working on a new project that needs to use Linq To SQL. I have been asked to create a generic or reusable Linq to SQL class that can be used to execute stored procedures.

In ADO.Net I knew how to do this by just passing in a string of what I wanted to execute and I could pass in different strings for each query I need to run:

SqlCommand cmd = new SqlCommand("myStoredProc", conn); // etc, etc

I am struggling with how to create something similar in Linq To SQL, if it is even possible. I have created a .dbml file and added my stored procedure to it. As a result, I can return the results using the code below:

public List<myResultsStoreProc> GetData(string connectName)
{
   MyDataContext db = new MyDataContext (GetConnectionString(connectName));
   var query = db.myResultsStoreProc();

   return query.ToList();
}

The code works but they want me to create one method that will return whatever stored procedure I tell it to run. I have searched online and talked to colleagues about this and have been unsuccessful in finding a way to create reusable stored proc class.

So is there a way to create a reusable Linq to SQL class to execute stored procs?

Edit:

What I am looking for is if there is a way to do something like the following?

public List<string> GetData(string connectName, string procedureName)
{
   MyDataContext db = new MyDataContext (GetConnectionString(connectName));
   var query = db.procedureName();

   return query.ToList();
}

I have reviewed the MSDN docs on Linq To Sql and these are showing the table in the IEnumerable:

IEnumerable<Customer> results = db.ExecuteQuery<Customer>(
   @"select c1.custid as CustomerID, c2.custName as ContactName
      from customer1 as c1, customer2 as c2
      where c1.custid = c2.custid"
);

I am looking for something very generic, where I can send in a string value of the stored proc that I want to execute. If this is not possible, is there any documentation on why it cannot be done this way? I need to prove why we cannot pass a string value of the name of the procedure to execute in Linq To Sql

Answer 1

DataContext.ExecuteCommand is not quite what you are looking for, as it only returns an int value. What you want instead is DataContext.ExecuteQuery, which is capable of executing a stored procedure and returning a dataset.

I would create a partial class for your DBML in which to store this function.

public List<T> GetDataNoParams(string procname)
{
   var query = this.ExecuteQuery<T>("Exec " + procname);

   return query.ToList();
}

public List<T> GetDataParams(string procname, Object[] parameters)
{
   var query = this.ExecuteQuery<T>("Exec " + procname, parameters);

   return query.ToList();
}

To call a stored procedure you would do:

GetDataNoParams("myprocedurename");

or

GetDataParams("myotherprocedure {0}, {1}, {2}", DateTime.Now, "sometextValue", 12345);

or

GetDataParams("myotherprocedure var1={0}, var2={1}, var3={2}", DateTime.Now, "sometextValue", 12345);

If you want to call procedures with no return value that is easy enough too, as I’m sure you can see, by creating a new method that doesn’t store/return anything.

The inspiration came from http://msdn.microsoft.com/en-us/library/bb361109(v=vs.90).aspx.