How do you get output parameters from a stored procedure in Python?

Question

I\'ve googled around a bit, but maybe I didn\'t put the correct magik incantation into the search box.

Does anyone know how to get output parameters from a stored p

Answer 1

If you make your procedure produce a table, you can use that result as a substitute for out params.

So instead of:

CREATE PROCEDURE Foo (@Bar INT OUT, @Baz INT OUT) AS
BEGIN
   /* Stuff happens here */
   RETURN 0
END

do

CREATE PROCEDURE Foo (@Bar INT, @Baz INT) AS
BEGIN
   /* Stuff happens here */
   SELECT @Bar Bar, @Baz Baz
   RETURN 0
END

Answer 2

Here's how I did it, the key is to declare output parameter first:

import cx_Oracle as Oracle

conn = Oracle.connect('xxxxxxxx')
cur = conn.cursor()

idd = cur.var(Oracle.NUMBER)
cur.execute('begin :idd := seq_inv_turnover_id.nextval; end;', (idd,))
print(idd.getvalue())

Answer 3

I'm not a python expert but after a brief perusing of the DB-API 2.0 I believe you should use the "callproc" method of the cursor like this:

cur.callproc('my_stored_proc', (first_param, second_param, an_out_param))

Then you'll have the result in the returned value (of the out param) in the "an_out_param" variable.

Answer 4

If you cannot or don't want to modify the original procedure and have access to the database you can write a simple wrapper procedure that is callable from python.

For example, if you have a stored procedure like:

CREATE PROC GetNextNumber
   @NextNumber int OUTPUT
AS
...

You could write a wrapper like so which is easily callable from python:

CREATE PROC GetNextNumberWrap
AS
    DECLARE @RNextNumber int
    EXEC GetNextNumber @RNextNumber
    SELECT @RNextNumber
GO

Then you could call it from python like so:

import pymssql
con = pymssql.connect(...)
cur = con.cursor()
cur.execute("EXEC GetNextNumberWrap")
next_num = cur.fetchone()[0]

Answer 5

I was able to get an output value from a SQL stored procedure using Python. I could not find good help getting the output values in Python. I figured out the Python syntax myself, so I suspect this is worth posting here:

import sys, string, os, shutil, arcgisscripting
from win32com.client import Dispatch
from adoconstants import *

#skip ahead to the important stuff

conn = Dispatch('ADODB.Connection')
conn.ConnectionString = "Provider=sqloledb.1; Data Source=NT38; Integrated Security = SSPI;database=UtilityTicket"
conn.Open()

#Target Procedure Example: EXEC TicketNumExists @ticketNum = 8386998, @exists output

Cmd = Dispatch('ADODB.Command')
Cmd.ActiveConnection = conn

Cmd.CommandType = adCmdStoredProc
Cmd.CommandText = "TicketNumExists"

Param1 = Cmd.CreateParameter('@ticketNum', adInteger, adParamInput)
Param1.Value = str(TicketNumber)
Param2 = Cmd.CreateParameter('@exists', adInteger, adParamOutput)

Cmd.Parameters.Append(Param1)
Cmd.Parameters.Append(Param2)

Cmd.Execute()

Answer = Cmd.Parameters('@exists').Value

Answer 6

You might also look at using SELECT rather than EXECUTE. EXECUTE is (iirc) basically a SELECT that doesn't actually fetch anything (, just makes side-effects happen).