Calling Oracle stored procedure from C#?

Question

How does one call a stored procedure in oracle from C#?

Answer 1

Instead of

cmd = new OracleCommand("ProcName", con);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add("ParName", OracleDbType.Varchar2, ParameterDirection.Input).Value = "foo";

You can also use this syntax:

cmd = new OracleCommand("BEGIN ProcName(:p0); END;", con);
cmd.CommandType = CommandType.Text;
cmd.Parameters.Add("ParName", OracleDbType.Varchar2, ParameterDirection.Input).Value = "foo";

Note, if you set cmd.BindByName = False (which is the default) then you have to add the parameters in the same order as they are written in your command string, the actual names are not relevant. For cmd.BindByName = True the parameter names have to match, the order does not matter.

In case of a function call the command string would be like this:

cmd = new OracleCommand("BEGIN :ret := ProcName(:ParName); END;", con);
cmd.CommandType = CommandType.Text;
cmd.Parameters.Add("ret", OracleDbType.RefCursor, ParameterDirection.ReturnValue);    
cmd.Parameters.Add("ParName", OracleDbType.Varchar2, ParameterDirection.Input).Value = "foo";
// cmd.ExecuteNonQuery(); is not needed, otherwise the function is executed twice!
var da = new OracleDataAdapter(cmd);
da.Fill(dt);