What is the correct usage of zxjdbc to call stored procedures?

Question

I am attempting to use zxJDBC to connect to a database running on SQL Server 2008 R2 (Express) and call a stored procedure, passing it a single parameter. I am using jython-standalone 2.5.3 and ideally do not want to have to install additional modules.

My test code is shown below.

The database name is CSM

Stored Procedure:

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- =============================================
-- Author:      <Author,,Name>
-- Create date: <Create Date,,>
-- Description: <Description,,>
-- =============================================
CREATE PROCEDURE dbo.DUMMY 
    -- Add the parameters for the stored procedure here
    @carrierId VARCHAR(50)
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    -- Insert statements for procedure here
    INSERT INTO dbo.carrier (carrierId, test)
    VALUES (@carrierId, 'Success')
END
GO

Jython Script:

from com.ziclix.python.sql import zxJDBC

conn = None
try :
    conn = zxJDBC.connect('jdbc:sqlserver://localhost\SQLEXPRESS', 'sa', 'password', 'com.microsoft.sqlserver.jdbc.SQLServerDriver')
    cur = conn.cursor()
    cur.callproc(('CSM','dbo','DUMMY'), ['carrier1'])
    conn.commit()
except Exception, err :
    print err
    if conn:
        conn.rollback()
finally :
    if conn :
        conn.close()

By using cur.execute() I have been able to verify that the above is successfully connecting to the database, and that I can query against it. However, I have thus far been unable to successfully call a stored procedure with parameters.

The documentation here(possibly out of date?) indicates that callproc() can be called with either a string or a tuple to identify the procedure. The example given -

c.callproc(("northwind", "dbo", "SalesByCategory"), ["Seafood", "1998"], maxrows=2)

When I attempt to use this method, I receive the following error

Error("Could not find stored procedure 'CSM.DUMMY'. [SQLCode: 2812], [SQLState: S00062]",)

It would appear that zxJDBC is neglecting to include the dbo part of the procedure identifier.

If I instead call callproc with "CSM.dbo.DUMMY" as the first argument then I receive this error

Error('An object or column name is missing or empty. For SELECT INTO statements, verify each column has a name. For other statements, look for empty alias names. Aliases defined as "" or [] are not allowed. Change the alias to a valid name. [SQLCode: 1038], [SQLState: S0004]',)

Using a profiler on the database whilst running my script shows that in the second case the following SQL is executed:

use []
go

So it would seem that when using a single string to identify the procedure, the database name is not correctly parsed out.

One of my trial and error attempts to fix this was to call callproc as follows:

cur.callproc(('CSM', '', 'dbo.DUMMY'), ['carrier1'])

This got me only as far as

Error("Procedure or function 'DUMMY' expects parameter '@carrierId', which was not supplied. [SQLCode: 201], [SQLState: S0004]",)

In this case what I think is happening is that zxJDBC attempts to call a system stored procedure (sp_proc_columns) to determine the required parameters for the stored procedure I want to call. My guess is that with the procedure identifier in the incorrect format above, zxJDBC does not get a valid/correct return and assumes no parameters are required.

So basically I am not a bit stuck for ideas as to how to get it to

• Use the correct database name
• Correctly determine the required parameters using sp_proc_columns
• Call my stored procedure with the correct name

all at the same time.

I do have a workaround, which is to use something like

cur.execute('EXEC CSM.dbo.DUMMY ?', ['carrier1'])

However I feel like callproc() is the correct solution, and would likely produce cleaner code when I come to call stored procedures with large numbers of parameters.

If anyone can spot the mistake(s) that I am making, or knows that this is not ever going to work as I think then any input would be much appreciated.

Thanks

Edit

As suggested by i-one, I tried adding cur.execute('USE CSM') before calling my stored procedure (also removing the database name from the procedure call). This unfortunately produces the same Object or Column missing error as above. The profiler shows USE CSM being executed, followed by USE [] so it seems that callproc() always fires a USE statement before the procedure itself.

I have also experimented with turning on/off autocommit, to no avail.

Edit 2

Further information following comments/suggested solutions:

• "SQLEXPRESS" in my connection string is the database instance name.
• Using double quotes instead of single has no effect.
• Including the database name in the connection string (via ;databaseName=CSM; as specified here) and omitting it from the callproc() call leads to the original error with a USE [] statement being fired.

Using callproc(('CSM', 'dbo', 'dbo.DUMMY'), ['carrier1']) gives me some progress but results in the error

Error("Procedure or function 'DUMMY' expects parameter '@carrierId', which was not supplied. [SQLCode: 201], [SQLState: S0004]",)

I'll attempt to investigate this further

Edit 3

Based on the queries I could see zxJDBC firing, I manually executed the following against my database:

use CSM
go
exec sp_sproc_columns_100 N'dbo.DUMMY',N'dbo',N'CSM',NULL,N'3'
go

This gave me an empty results set, which would seem to explain why zxJDBC isn't passing any parameters to the stored procedure - it doesn't think it needs to. I have yet to figure out why this is happening though.

Edit 4

To update the above, the empty result set is because the call should be

exec sp_sproc_columns_100 N'DUMMY',N'dbo',N'CSM',NULL,N'3'

This unfortunately brings me full circle as I can't remove the dbo owner from the stored procedure name in my callproc() call or the procedure won't be found at all.

Edit 5

Table definition as requested

CREATE TABLE [dbo].[carrier](
    [carrierId] [varchar](50) NOT NULL,
    [test] [varchar](50) NULL
) ON [PRIMARY]

Answer 1

Though completely unaware of the technologies used here (unless some minor knowledge of SQL Server), I will attempt an answer (please forgive me if my jython syntax is not correct. I am trying to outline possibilities here not exact code)

My first approach (found at this post) would be to try:

cur.execute("use CSM")
cur.callproc(("CSM","dbo","dbo.DUMMY"), ["carrier1"])

This must have to do with the fact that sa users always have the dbo as a default schema (described at this SO post)

If the above does not work I would also try to use the CSM database name in the JDBC url (this is very common when using JDBC for other databases) and then simply call one of the two below.

cur.callproc("DUMMY", ["carrier1"])
cur.callproc("dbo.DUMMY", ["carrier1"])

I hope this helps

Update: I quote the relevant part of the link that you can't view

>> Program calls a Stored Procedure - master.dbo.xp_fixeddrives on  MS SQL Server

from com.ziclix.python.sql import zxJDBC

def getConnection():
    url = "${DBServer.Url}"
    user= "${DBServer.User}"
    password = "${DBServer.Password}"
    driver = "${DBServer.Driver}"
    con = zxJDBC.connect(url, user, password, driver)
    return con

try:
    conn = getConnection()
    print 'Connection successful'
    cur = conn.cursor()
    cur.execute("use master")
    cur.callproc(("master", "dbo", "dbo.xp_fixeddrives"))
    print cur.description
    for a in cur.fetchall():
        print a
finally:
    cur.close()
    conn.close()
    print 'Connection closed'

The error you get when you specified the call function like above suggests that the parameter is not passed correctly. So please modify your stored procedure to take a default value and try to call with passing params = [None]. If you see that the call succeeds we must have done something right as far as specifying the database is concerned. Btw: the most recent documentation suggests that you should be able to access it with your syntax.

Answer 2

As outlined in comments callproc will work only with SELECT. Try this approach instead:

cur.execute("exec CSM.dbo.DUMMY @Param1='" + str(Param1) + "', @carrierId=" + str(carrierID))

Please see this link for more detail.