Create new SQLCommand's or reuse the same one

Question

I need to send a list of commands to SQL 2008 using ADO.NET, to be executed one after the other. Should I create a new SQLCommand for each SQL that I'm sending? Or reuse the same SQLCommand and just change the CommandText property? Thanks, Nestor

Answer 1

SqlCommands are pretty light-weight. You are safe to create a new one each time.

There are complications with parametrized commands where you need to clear and reset all parameters, and at that point, creating a new command is clean, easy to understand, and effective.

In addition, it is usually OK to use a new SqlConnection each time as well. The automatic, built-in connection pooling is the "magic" that makes this efficient.

I use this:

public void ExecuteQuery(string query)
{
    this.ExecuteQuery(query, null);
}

public void ExecuteQuery(string query, Dictionary<string, object> parameters)
{
    using (SqlConnection conn = new SqlConnection(this.connectionString))
    {
        conn.Open();

        using (SqlCommand cmd = conn.CreateCommand())
        {
            cmd.CommandText = query;

            if (parameters != null)
            {
                foreach (string parameter in parameters.Keys)
                {
                    cmd.Parameters.AddWithValue(parameter, parameters[parameter]);
                }
            }

            cmd.ExecuteNonQuery();
        }
    }
}