Executing Table-Valued SQL Functions in .NET: Stored Procedure Method Possible?

Data and Databases
1

I know how to use scalar-valued SQL functions in .NET by setting up a SqlCommand like a stored procedure. It works well when retrieving a single value. For table-valued functions, however, I usually write a SQL query to select from the function and use a SqlDataAdapter to fill a DataTable. Now I’m curious if there is a way to treat table-valued functions as stored procedures, similar to scalar functions, and receive the table through a ReturnValue parameter.

For example:

// Example for a scalar function, is there a similar method for table-valued functions?
var cmd = new SqlCommand("myTableFunction", connection);
cmd.CommandType = CommandType.StoredProcedure;
// Set up parameters...
cmd.ExecuteNonQuery();
// How do we get the resulting table here?

Is this approach possible, or must we continue using the SELECT query method?

2

hmm, interesting question! have you considered using SqlCommand.ExecuteXmlReader()? it might work for table-valued functions, returning results as XML. could be worth a shot! what do you think about exploring that approach? curious to hear if anyone else has tried it successfully.

3

hey, try ExecuteReader() instead of ExecuteNonQuery(). you get a SqlDataReader to process rows from your tv function. e.g.: var cmd = new SqlCommand(‘myTableFunction’, connection); cmd.CommandType = CommandType.StoredProcedure; using(var r = cmd.ExecuteReader()){ // process } hope this helps!

4

While it’s not directly possible to treat table-valued functions as stored procedures in .NET, you can achieve similar functionality using a slightly different approach. Instead of ExecuteNonQuery, you can use ExecuteReader to retrieve the results of a table-valued function.

Here’s how you could modify your code:

var cmd = new SqlCommand("myTableFunction", connection);
cmd.CommandType = CommandType.StoredProcedure;
// Set up parameters if needed

using (var reader = cmd.ExecuteReader())
{
    // Process the results here
    // You can read row by row or load into a DataTable
}

This method allows you to work with the table-valued function results directly, without needing to write a separate SELECT query. It’s efficient and maintains a similar structure to how you’re handling scalar functions.