Shamil Salakhetdinov
shamil at users.mns.ru
Wed Feb 21 17:40:40 CST 2007
No problem, Eric, I anyway planned to write a short note here on ADODB and
parameterized stored procedures...
BTW, for parameterized UDFs ADODB can be also used but the issue with access
permissions usually forces to use stored procedures - I mean UDF can't be
used with a table if a user does not have access permissions for this table.
As for stored procedure - it can be used with a table even if a user does
not have access permission to this table - user should only have a
permission to execute this stored procedure.
Here is an example with parameterized UDF and ADODB - parameters's values in
this sample are hardcoded in select expression:
Dim cnn As ADODB.Connection
Dim strCnn As String
Dim cmd As ADODB.Command
Dim prm As ADODB.Parameter
Dim rst As ADODB.Recordset
strCnn = "Provider=sqloledb;Data Source=(local);Initial
Catalog=Northwind;Integrated Security=SSPI;"
Set cnn = New ADODB.Connection
cnn.Open strCnn
cnn.CursorLocation = adUseClient
Set cmd = New ADODB.Command
cmd.CommandType = adCmdText
cmd.CommandText = "select * from TotalFreightStats( _
'1996-07-02', '1996-07-12')"
cmd.ActiveConnection = cnn.ConnectionString
Set rst = cmd.Execute
While Not rst.EOF
Debug.Print rst(0).Value & " - " & rst(1).Value
rst.MoveNext
Wend
cnn.Close
--
Shamil
-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Eric Barro
Sent: Thursday, February 22, 2007 1:51 AM
To: 'Access Developers discussion and problem solving'
Subject: Re: [AccessD] Feeding parameters to SQL Server
Uh..hmmm...Jim and Shamil...I was replying to Colby's question on passing
parameters to SQL which was the original thread.
Someone suggested pass-thru queries somewhere in the thread. I just happened
to reply to the last message in the thread that came from Shamil.
-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Jim Lawrence
Sent: Wednesday, February 21, 2007 2:48 PM
To: 'Access Developers discussion and problem solving'
Subject: Re: [AccessD] Feeding parameters to SQL Server
Eric
My recommendation is do not use pass-through queries. They are more problem
than they are worth as they seem to be an easy quick fix to start with but
end up being slow, awkward and unstable.
I believe this set of processes was designed to punish newbie developers
scaring them off weaning from a MDB BE. MS should have simply remove that
whole gambit of functions from Access and never bring them up again in
polite company.
Now if you want my unvarnished opinion on the subject don't be afraid to
ask. :-)
Jim
-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Eric Barro
Sent: Wednesday, February 21, 2007 1:47 PM
To: 'Access Developers discussion and problem solving'
Subject: Re: [AccessD] Feeding parameters to SQL Server
Unfortunately dynamic parameters and sql pass-thru queries don't play well
in Access.
http://www.utteraccess.com/forums/showflat.php?Board=82&Number=1361479
-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Shamil
Salakhetdinov
Sent: Wednesday, February 21, 2007 1:00 PM
To: 'Access Developers discussion and problem solving'
Subject: Re: [AccessD] Feeding parameters to SQL Server
Hello John,
Let's suppose you use NorthWind sample database and you have to calculate
total Freight for a Shipper given from/to dates.
I assume you do not use ADPs - if you have used them then you could have
created
- a stored procedure:
=====================
CREATE PROCEDURE usp_TotalFreightStats (@fromDate datetime, @toDate datetime
)
AS
BEGIN
select ShipName, Sum(Freight) as FreightTotal
from Orders
where Orders.OrderDate between @fromDate and @toDate
Group by ShipName
END
- or a UDF
===========
CREATE FUNCTION TotalFreightStats (@fromDate datetime, @toDate datetime )
RETURNS @TotalFreightStatsTable TABLE
(
ShipperName nvarchar(80),
TotalFreight money
)
AS
BEGIN
declare @fromDate1 dateTime
declare @toDate1 dateTime
INSERT @TotalFreightStatsTable
select ShipName, Sum(Freight) as FreightTotal
from Orders
where Orders.OrderDate between @fromDate and @toDate
Group by ShipName
RETURN
END
And you could have bound your report to this stored procedure or UDF - on
open this report would have requested from/to dates in parameters input
dialog.
I assume you use mdb and then you can:
- create table to keep parameters
==================================
CREATE TABLE [dbo].[ParametersForUDFs] (
[fromDate] [datetime] NULL ,
[toDate] [datetime] NULL
) ON [PRIMARY]
GO
- populate this table with parameters' values (clear in first)
=============================================================
delete from ParametersForUDFs
insert into ParametersForUDFs (fromDate, toDate) values ('1996-07-04',
'1996-07-12')
- create UDF
============
CREATE FUNCTION TotalFreightStats1 ( )
RETURNS @TotalFreightStatsTable TABLE
(
ShipperName nvarchar(80),
TotalFreight money
)
AS
BEGIN
INSERT @TotalFreightStatsTable
select ShipName, Sum(Freight) as FreightTotal
from Orders
where Orders.OrderDate
between (select top 1 fromDate from ParametersForUDFs)
and (select top 1 toDate from ParametersForUDFs)
Group by ShipName
RETURN
END
- use UDF in view
==================
CREATE VIEW dbo.vw_TotalFreightStats1
AS
SELECT ShipperName, TotalFreight
FROM dbo.TotalFreightStats1() TotalFreightStats1
++++++++++++++++++++++++++++++++++++
- link view to MS Access mdb
++++++++++++++++++++++++++++++++++++
Of course that approach will not work well in multi-user environment if
different users will need different from/to dates...
--
Shamil
-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of JWColby
Sent: Wednesday, February 21, 2007 10:11 PM
To: 'Access Developers discussion and problem solving'
Subject: Re: [AccessD] Feeding parameters to SQL Server
Well... I dunno.
I have a view in SQL Server returning 8 fields, 6K records (currently),
completely unfiltered, all records in the table. I pull that linked table
into a query in order to do some preliminary filtering - check date between
a pair of dates and check number not null.
I want the view in sql server to do the "check number not null" for me, and
I know how to do that.
I want the SQL Server to take a pair of parameters - "From Date" and "To
Date" and return only those records.
If I could do this, then I could get rid of my "base query" in access which
applies these filters, reduce traffic across the wire etc. However even if
I do this, the view is not being requested by a form in XP (for example)
where some magical thing happens in Access to pass the parameters off to SQL
Server. The linked view will be used immediately in another query which
joins this view to other tables (on one field - BEID - in the view) in order
to build up a set of data for a report.
So the "parent" query that is using the view will have to "feed" the
parameters to the linked view. Being a nubee to SQL Server I do not even
know if what I am attempting to do is possible. I cannot wrap my mind
around how a query that is using a view can know that the view needs
parameters, and if it did, what to feed it. If it is possible, I have never
done so obviously, so I don't even have the basics of what to set in Access
to do the parameter passing.
John W. Colby
Colby Consulting
www.ColbyConsulting.com
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