Multiple SQL queries asp.net c#

Question

I need to run several queries inside one function, will I have to create a new SqlConnection for each? Or having one connection but different SqlCommands works too?

Answer 1

Open only one SQLConnection

Use the keyworkd Using as it will automatically dispose the connection.

If you open connection for each one , it can have performance problems.

Example:

using (SqlConnection con = new SqlConnection(connectionString))
    {
        //
        // Open the SqlConnection.
        //
        con.Open();
        //
        // The following code shows how you can use an SqlCommand based on the SqlConnection.
        //
        using (SqlCommand command = new SqlCommand("SELECT TOP 2 * FROM Dogs1", con))
        using (SqlDataReader reader = command.ExecuteReader())
        {
        while (reader.Read())
        {
            Console.WriteLine("{0} {1} {2}",
            reader.GetInt32(0), reader.GetString(1), reader.GetString(2));
        }
        }
    }

One more example:

public  DataTable GetData()
        {
            DataTable dt = new DataTable();
            using (SqlConnection con = new SqlConnection("your connection here")
            {
                con.Open();
                using (SqlCommand cmd = con.CreateCommand())
                {
                    cmd.CommandType = CommandType.StoredProcedure;
                    cmd.CommandText = "your stored procedure here";                    
                    using (SqlDataAdapter da = new SqlDataAdapter(cmd))
                    {
                        da.Fill(dt);
                    }
                }
            }
            return dt;
        }