reading parameters in C#

Something to this effect:


SqlConnection cnPubs = new SqlConnection("server=localhost;integrated security=true;database=pubs");

SqlCommand cmdAuthors = new SqlCommand("up_AuthorBookCount", cnPubs);

cmdAuthors.CommandType = CommandType.StoredProcedure;

cmdAuthors.Parameters.Add("@au_id", SqlDbType.NVarChar, 11);
cmdAuthors.Parameters["@au_id"].Value = AuthorID;

cmdAuthors.Parameters.Add("@Count", SqlDbType.Int);
cmdAuthors.Parameters["@Count"].Direction = ParameterDirection.Output;

cnPubs.Open();
int iCount;
cmdAuthors.ExecuteNonQuery();
iCount = (int) cmdAuthors.Parameters["@Count"].Value;
cnPubs.Close();

Originally posted by Unpossible
could you please explain this piece in detail? as in whats happening

The first line of each "pair" is defining a parameter which the stored procedure needs.

Earlier data-access libraries queried the DB and figured out what parameters were needed -how many, what they were named, what datatype, what "direction" (input, output, return val), and so on, so all you had to do was supply the values.

However, this was actually quite poor in performance terms, so they decided it was a better approach to make the developer specifically state what parameters he wants, how many, what direction, what they're called, and so on and so forth.

The second line of each pair is actually supplying a value for each parameter.

jc