MySQLConnector c# update MySqlCommand parameters

Question

I have a foreach loop in C# which execute a MySQL command to check if the result exist, the problem is I don't know how to update the value in the parameters corresponding to @id_line an error is thrown at the second iteration

foreach (String[] infos in ReferenceLine.getList())
{
    cmd.Parameters.AddWithValue("@id_line", infos[0].ToString());
    using (MySqlDataReader reader = cmd.ExecuteReader())
    {
        if (reader.HasRows) { return true; }
    }
}

I thought of checking if the value exists and deleting it but I don't find this solution clean

Thanks

Answer 1

Move the declaration of the parameter outside the loop without giving an explicit value, then inside the loop just update the Value property without redeclaring the parameter

cmd.Parameters.AddWithValue("@id_line", "");
foreach (String[] infos in ReferenceLine.getList())
{

    cmd.Parameters["@id_line"].Value = infos[0].ToString();
    using (MySqlDataReader reader = cmd.ExecuteReader())
    {
        if (reader.HasRows) { return true; }
    }
}

However, it seems possible to completely avoid this loop with a more precise query with a WHERE condition.

Consider also to use

 cmd.Parameters.Add("@id_line", MySqlDbType.VarChar);

instead of AddWithValue. AddWithValue has some drawbacks that suggest to limit its use.