SqlCommand

[moein serpico]

hi where i should use SqlCommand.Parameters.Add()method and where SqlCommand.Parameter.AddWithValue()? is there performance diffrence?

[mersad00]

Hi, Specially parameters used to pass data to ur query , as inset update delete even select

select *
from t1
where id = 12

this query always returns a fixed result, now going to make it gloabal, i mean change the 12 value to needed value, so u use parameters as:

select *
from t1
where id=@id

now in command line, u must set the parameter, look at this method as a sample:

    private DataTable SelectParameter(int idvalue, bool useWithvalue)
    {
        string constr = "";
        SqlConnection con = new SqlConnection(constr);
        SqlCommand cmd = new SqlCommand("select \* from t1 where id=@id", con);

        if (useWithvalue)
        {
            cmd.Parameters.AddWithValue("@id", idvalue);
           
        }
        else
        {
           
            SqlParameter p = new SqlParameter("@id", SqlDbType.Int);
            p.Value = idvalue;
            cmd.Parameters.Add(p);
        }

        con.Open();
        DataTable dt = new DataTable();
        dt.Load(cmd.ExecuteReader());
        return dt;

    }

in cases that u are going to set the value type of parameter u should use add else u could use both of them.

[PIEBALDconsult]

I hear that AddWithValue is kinda safer, but I rarely use it because of the way I do things. It's not a performance issue.

[Searril]

I like .AddWithValue just to save keystrokes, but never noticed any performance difference either way.