C# MySql Parameterized Query makes longs into null

Question

The code is based on https://dev.mysql.com/doc/connector-net/en/connector-net-programming-prepared-preparing.html

 public void TableTest(string connectionString)
    {
        string sqlToCreateTable = @"CREATE TABLE IF NOT EXISTS my_table 
            (auction_key BIGINT NOT NULL, auction_owner VARCHAR(25),     first_seen BIGINT, 
            PRIMARY KEY(auction_key))";

        string sqlInsertOrUpdateAuction = "INSERT INTO my_table (auction_key)  VALUES (@my_auc_id); ";

        using (MySqlConnection dbConnection = new MySqlConnection(connectionString))
        {
            dbConnection.Open();

            // is the table in the database?
            MySqlCommand cmd = new MySqlCommand(sqlToCreateTable, dbConnection);
            cmd.ExecuteNonQuery();

            cmd.Parameters.AddWithValue("@my_auc_id", 123456);
            cmd = new MySqlCommand(sqlInsertOrUpdateAuction, dbConnection);
            cmd.ExecuteNonQuery();

        }
    }

The error is that 123456 is seen as null.

Message=Column 'auction_key' cannot be null

I tried changing the "strict" setting in my.ini and it makes no difference.

Help please.

Answer 1

Well, you add the parameter to the command and then instantiate a new command:

cmd.Parameters.AddWithValue("@my_auc_id", 123456);
cmd = new MySqlCommand(sqlInsertOrUpdateAuction, dbConnection);

If you do that, the command will no longer have the value for the @my_auc_id. Try switching those two lines:

cmd = new MySqlCommand(sqlInsertOrUpdateAuction, dbConnection);
cmd.Parameters.AddWithValue("@my_auc_id", 123456);

Hope this helps.