Can I display the result of stored procedure in ASP.NET?

Question

Here's my stored procedure, in which I'm inserting records to a database and, if a record exists, it gets updated. Can I get result back, like how many records are updated and how many records are inserted?

// stored procedure

ALTER PROCEDURE [dbo].[Update_F3_BC_Column_Mapping]
@tblF3_BC_Column_Mapping F3_BC_Column_MappingType READONLY
AS
BEGIN
SET NOCOUNT ON;
MERGE INTO F3_BC_Column_Mapping c1
USING @tblF3_BC_Column_Mapping c2
ON c1.Id=c2.Id
WHEN MATCHED THEN
UPDATE SET c1.Source = c2.Source
      ,c1.Destination = c2.Destination
WHEN NOT MATCHED THEN
INSERT VALUES(c2.Id, c2.Source, c2.Destination);
END


//c# code

connection();
{
    using (SqlCommand cmd = new SqlCommand("Update_F3_BC_Column_Mapping"))
    {
        cmd.CommandType = CommandType.StoredProcedure;
        cmd.Connection = con;
        cmd.Parameters.AddWithValue("@tblF3_BC_Column_Mapping", dtMap);
        con.Open();
        cmd.ExecuteNonQuery();
        con.Close();
    }
}

Answer 1

To get 2 different numbers, inserted and updated, you can alter your stored procedure to allow a couple of output variables, and handle them as parameters in c#.

In the header of your procedure, add 2 output parameters:

ALTER PROCEDURE [dbo].[Update_F3_BC_Column_Mapping]
@tblF3_BC_Column_Mapping F3_BC_Column_MappingType READONLY,
@updated_count int output,
@inserted_count int output
AS

In the body, declare a table variable to hold the output from the merge;

BEGIN
    SET NOCOUNT ON;
    declare @outputtable table ([action] nvarchar(10), [count] int);

And then add a (last) line to the merge to fill this table:

    MERGE INTO F3_BC_Column_Mapping c1
    USING @tblF3_BC_Column_Mapping c2
        ON c1.Id=c2.Id
    WHEN MATCHED THEN
        UPDATE SET c1.Source = c2.Source
              ,c1.Destination = c2.Destination
    WHEN NOT MATCHED THEN
        INSERT VALUES(c2.Id, c2.Source, c2.Destination)
    OUTPUT $action , 1   INTO @outputtable;

Now you can populate your output variables by counting rows in this output table to end your stored procedure:

    select @updated_count = sum([count]) from @outputtable where [action] = 'UPDATE';
    select @inserted_count = sum([count]) from @outputtable where [action] = 'INSERT';
END

(All of the code rows posted so far make up your new stored procedure.)

You now need to add 2 additional parameters to you c# code:

connection();
{
    using (SqlCommand cmd = new SqlCommand("Update_F3_BC_Column_Mapping"))
    {
        cmd.CommandType = CommandType.StoredProcedure;
        cmd.Connection = con;
        cmd.Parameters.AddWithValue("@tblF3_BC_Column_Mapping", dtMap);

        cmd.Parameters.Add("@updated_count", SqlDbType.Int).Direction = ParameterDirection.Output;
        cmd.Parameters.Add("@inserted_count", SqlDbType.Int).Direction = ParameterDirection.Output;

And after you have run your query, you can access the outputs by using the value property:

        con.Open();
        cmd.ExecuteNonQuery();

        int updated = Convert.ToInt32(cmd.Parameters["@updated_count"].Value);
        int inserted = Convert.ToInt32(cmd.Parameters["@inserted_count"].Value);

and then finish off your code:

        con.Close();
    }
}

Answer 2

Based on MSDN :

For UPDATE, INSERT, and DELETE statements, the return value is the number of rows affected by the command. When a trigger exists on a table being inserted or updated, the return value includes the number of rows affected by both the insert or update operation and the number of rows affected by the trigger or triggers. For all other types of statements, the return value is -1. If a rollback occurs, the return value is also -1.

So you just need to store the ExecuteNonQuery 's return value in a variable like this:

int count = cmd.ExecuteNonQuery();