Oracle/VB question - same newbie different question.

Question

Hi,
I've just learned the magic that is getting VB to call stored procedures in Oracle - but now I have a question.
I have a procedure that runs through a table, this is the loop part :
loop
fetch staff_c into surname_str, first_str, salary_str;
exit when staff_c%notfound;
dbms_output.put_line('data ' || surname_str || ', ' || first_str || ' - ' || salary_str);
end loop;
close staff_c;
so my question is simply this, I'm using the following VB code to access a stored procedure which is passing a param in, and a param out -
Dim cmd As ADODB.Command
Dim conn As ADODB.Connection
Dim param As ADODB.Parameter
Set conn = New ADODB.Connection
conn.Open "dsn=PaulsRescueDB", "x", "y"
Set cmd = New ADODB.Command
cmd.ActiveConnection = conn
cmd.CommandType = adCmdStoredProc
cmd.CommandText = "lang_count"
Set param = cmd.CreateParameter("@p_in", adVarChar, adParamInput, 10, "english")
cmd.Parameters.Append param
cmd.Execute
MsgBox cmd.Parameters(1).Value
conn.Close
what do I need to do in order to be able to treat the result of the stored procedure as a recordset - or am I mis-understanding something?
Thanks in advance,
Ed.

Answer 1

Just in case anyone else out there was interested here's a brief summary of the solution.
First lets look at the stored procedure as this is where the first and most important point is to be seen:
create or replace package types
as
type cursorType is ref cursor;
end;
so we're creating a cursor type variable called cursortype, this is then used in the following code:
create or replace procedure getemps( p_in in varchar, p_cursor in out ref cursor
as
begin
open p_cursor for select surname, firstname
from staff
where initcap(p_in) = surname;
end;
It should be noted that a cursor is effectively an area of memory specific to your session that stores a result set, the cursor is treated as a variable/object.
In the case of the above code the cursor contains the result of the select statement.
You will also notice that the code opens the cursor with the contents of the select (this is because whenever you create an object it is null - unless you give it an initial value).
The variable P_In is a varchar (when defining a procedure you do not specify the size of an int or varchar) and p_cursor is the returned data.
I do not know why p_cursor is both in and out, out alone would have been the obvious choice.
So we now have a stored procedure that takes a parameter to pass to a select statement, does a search and then returns a resultset (cursor).
Now to answer the original question, how do you use this in VB?
The code below illustrates (ADO):
Dim cmd As ADODB.Command
Dim conn As ADODB.Connection
Dim param As ADODB.Parameter
Dim rs As ADODB.Recordset
Set conn = New ADODB.Connection
conn.Open "dsn=PaulsRescueDB", "x", "y"
Set cmd = New ADODB.Command
cmd.ActiveConnection = conn
cmd.CommandType = adCmdStoredProc
cmd.CommandText = "getemps"
Set param = cmd.CreateParameter("@p_in", adVarChar, adParamInput, 10, "foghorn")
cmd.Parameters.Append param
Set rs = cmd.Execute
While Not rs.EOF
Debug.Print (rs.Fields(1).Value & " " & rs.Fields(0).Value)
rs.MoveNext
Wend
conn.Close
As you can see I am manually creating an ADODB object, specifying that the commandtype is a stored procedure and then appending a parameter to the command text.
You will also notice that although the cursor is the second parameter in the stored procedure I do not specify it directly but rather assign the ADO recordset object as the result of the ADO command execution.
Once I've done this I merely use the recordset as a normal recordset object.
CREDITS:
The stored procedure is based on the one supplied by Jens Link in the previous post.
The VB is a hijacked piece of ASP code modfied for VB.
If this helps anyone else out there besides me then I'm happy to have been able to give something back to the community that has helped me.
Ed.