How to access SQL Server scalar functions in MS Access VB - sql-server

I'm trying to find out how I can access scalar functions from the SQL Server database of my adp file.
I have an adp file in access 2007 and a SQL Server 2005 DB.
In access VB I try to get the result of a scalar function with parameters.
I tried with DAO, but it that case currentdb = nothing:
Dim dbs As DAO.Database
Dim sql2 As String
Dim txt As String
Dim iCount As Integer
Set dbs = CurrentDb
txt = "SELECT * FROM dbo.TBL_Klanten" '(tbl_klanten is in the msql DB) '
dbs.Execute txt, dbFailOnError

DAO was never designed to access sql server even though its possible.
I believe the CurrentDB property is a DAO connection referencing the access database, and may not work with ADP, even though I don't really know since I've never used them.
ADO is the way you want to go with this.
I'm also assuming you're sticking with VBA rather than doing anything with .NET.
ADO API reference
ADO Objects reference

Related

Return Select Queries Using ADO and Provider = SQLOLEDB

My ultimate goal is to run sql queries against sql-server and capture the returned data in a spreadsheet. The following code roughly reflects my current set-up and it works. The design allows me to read sql codes from text files and submit it to a sql-server. "Sub ExecuteCRUD" submits a first sql script to prepare data and dumps the result into a temp table. "Function loadRecordset" submits a relatively simple select query and captures the returned data in a recordset, which I then use to populate a spreadsheet.
There are a couple "variables" in my setup that could potentially be relevant for discussion.
My 4 set of Sql Codes
The ConnectionString (Part of my vba code)
The rest of my vba codes
a. Dbo.ConnectionString = "Provider=MSDASQL;DRIVER=SQL
Server;SERVER=myserver;UID=id;PWD=password;DATABASE=database;"
b. Dbo.ConnectionString = "Provider=SQLOLEDB;Data
Source=myserver;Initial Catalog=database;User
ID=id;Password=password;"
Initially, all I changed was the connection string. The immediate result was connection string version a works perfectly. Using b version, my setup would fail without any errors from sql-server.
Using Connection string version b, "Sub ExecuteCRUD" (data preparation step) would still work smoothly. I can verify that the temp table is created in tempdb as a result of my first sql script.
"Function loadRecordset" would run through the lines without any errors up to and including "rs.open". (I checked for errors, none whatsoever from the ado connection).
Only subsequent codes, when using the recordset to copy out the data would get an error: "Operation is not allowed when the object is closed."
Through some testing, I narrowed down the issue to the sql codes, sort of.
I have to reiterate here. My initial set of sql codes worked completely fine when using the ODBC provider. Things only went sideways using the OLEDB provider.
Using the OLEDB provider, the "offending" sql code was Use databaseABC. Furthermore, using ado, my setup submits 4 sets of sql codes to the sql server. The first set of sql codes prepares data (creating tables, inserting data, creating index, using while loops to populate data, using recursive ctes, etc). In this first set of sql codes, Use databaseABC was also included, and it would execute successfully. The other 3 set of sql codes submitted were only select queries aimed at obtaining data. When Use databaseABC was included in the select query sql codes, the operation failed without any errors. After I took out the Use databaseABC, everything would run correctly in the OLEDB provider world.
Use databaseABC is not a necessary part of the select queries. Using it saves me the trouble of specifying database names all the time in the join clauses.
At this point, my curiosity is two fold
why Use databaseABC causes failures, specifically only when using OLEDB provider, more specifically only when running select queries.
When the failure occurred, should sql-server or the driver generate any errors? What would be the proper way of checking and verifying that?
Private Dbo As New ADODB.Connection
Private rs As ADODB.Recordset
Public Sub ConnectServer()
If Dbo.State = adStateClosed Then
Dbo.ConnectionString = "Provider=SQLOLEDB;Data Source=*server*;" _
& "Initial Catalog=*database*;User ID=*id*;Password=*pwd*;"
Dbo.Open
End If
End Sub
Public Sub ExecuteCRUD(ByVal Sql As String)
On Error GoTo PANIC
Dbo.Execute Sql
Exit Sub
PANIC:
Debug.Print Err.Descript
Stop
End Sub
Public Function loadRecordset(ByVal Sql As String) As Long
On Error GoTo PANIC
Set rs = New ADODB.Recordset
With rs
.CursorLocation = adUseClient
.CursorType = adOpenStatic
.LockType = adLockReadOnly
.Source = Sql
Set .ActiveConnection = Dbo
End With
rs.Open
loadRecordset = rs.RecordCount
Exit Function
PANIC:
Debug.Print Err.Description
loadRecordset = 0
Stop
End Function

Transfer table from Ms-Access to SQL Server

I don't have much experience with SQL Server, I use it currently to run some simple queries, and I link to SQL tables from Access where I have all my heavy queries. My goal is to run all of my queries in Access daily and then at the end write the finished tables up to SQL where my Access front end will read them (versus keeping them in my Access backend).
I've tried messing around with the code below to try and figure out how to do this, but I'm stuck at the driver and I can't find any references on how to do this with just a single table. Let's call it "PO_STATUS_TBL"
Public Sub ADOtest()
Dim ADOConn As New ADODB.Connection
Dim ADOCom As New ADODB.Command
On Error Resume Next
ADOConn.ConnectionString = "Driver =(SQL Server);DRIVER=SQL Server;SERVER=BUSINESS_BWP;Trusted_Connection=Yes"
ADOConn.Open
Debug.Print ADOConn.State
Dim db As Database
Set db = CurrentDb
'db.Execute "INSERT INTO [ODBC;DRIVER=SQL Server;ENCSQL28\BUSINESS_BWP;DATABASE=CurrentDb].SFTransfersDB ( ID, TO ) SELECT ID,TO FROM SFTransfersDB"
End Sub
I went through this process lately.
For migration you can use this tool by Microsoft. With this tool you can either migrate a table or a query to MS-SQL - or even both. Even with relations.
Simple export with this wizard and add your one table through ODBC Connector in Access. Important is to have the correct ODBC Driver.
If you are interested I resolved this issue with Parfait's advise. By using a simple INSERT statement.
INSERT INTO Dbo_PO_STATUS_ALL_TBL Select * FROM PO_STATUS_ALL_TBL

Error 3035 when querying linked table in Access

I get error 3035: 'System Resource Exceeded' when executing the following sub:
Private Sub delete_result_staging()
Dim db As DAO.Database
Dim qdf As DAO.QueryDef
Set db = CurrentDb
Set qdf = db.QueryDefs("qryWQPassthrough")
qdf.Connect = Me.con_str.Value
qdf.ReturnsRecords = False
qdf.SQL = "TRUNCATE TABLE tblWQResultStaging;"
qdf.Execute
Set qdf = Nothing
Set db = Nothing
End Sub
I am using MS Access 2013 and SQL Server 2012.
This code has worked previously; it stopped working when I refactored another sub per How to increase performance for bulk INSERTs to ODBC linked tables in Access?. I have changed the MaxLocksPerFile to 1,000,000 in the registry per other suggestions on the internet. I restarted Access and my computer, and I still get the error every time the sub fires. In the SQL Server Profiler I see no activity on the server when the code is executed. Forms and reports that point to linked tables on the same server but are connected via the GUI, rather than through VBA, still work as expected.
I figured out the issue was that I was reusing a single passthrough query multiple times in VBA. It didn't like the SQL statement that was in the query from the last time I used it in code, so it threw the error. Looks like I need to either be more careful with my earlier VBA code that uses that query, or use separate queries for every VBA sub, or both.

Get Connection string for Pass through queries

I have just learned about the pass through queries in MS-ACCESS.
I have a SQL SERVER backend and
if I'm right, for a query access loads all records before to do the where clause... so what would be the point of having a SQL SERVER backend?
That's why I want to try using pass through queries as much as possible but is there a way I can get the connection string from my linked tables for my pass through queries?
I tried CurrentDb.TableDefs("One of my table name").Connect in the ODBC Connect Str property but I got the error saying it's an invalid connection string.
It would be nice because I know I will have to change the connection soon so I wouldn't have to edit the connection string at many places.
Thank you.
I'm not sure what you meant here: "for a query access loads all records before to do the where clause"
If the WHERE clause can be applied at the server, ODBC will translate it to the server's language, and only the matching rows will be sent back to Access:
WHERE date_field >= #2011-01-01# AND date_field < #2012-01-01#
That WHERE clause would limit the rows sent to Access to only those whose date_field values are from 2011.
However, if a WHERE clause includes functions which must be evaluated by Access, ODBC must retrieve all candidate rows and hand them over to the Access db engine so it can perform the evaluation.
WHERE Format(date_field, 'yyyy') = '2011'
But for your actual question ... connection string for pass through queries ... consider the following code example. I have an ODBC link named dbo_foo whose source table in SQL Server is [dbo].[foo]. So I can grab the .Connect property from dbo_foo and use it for the .Connect property of a pass through query based on the same server table.
Public Sub CreatePassThruQuery()
Dim db As DAO.Database
Dim qdf As DAO.QueryDef
Dim strConnect As String
Set db = CurrentDb
strConnect = db.TableDefs("dbo_foo").Connect
Set qdf = db.CreateQueryDef("qryDbo_Foo")
qdf.Connect = strConnect
qdf.SQL = "SELECT * FROM [dbo].[foo];"
qdf.Close
Set qdf = Nothing
Set db = Nothing
End Sub
Still when you change the .Connect property of the table, you will also need to do it for the query. If you have many of them and/or change the connections frequently, it may be worth the effort to create a VBA procedure to update them. Alternatively, you might use a DSN for the .Connect property of the table and matching query. Then revise the DSN as needed. A pitfall with that approach is that, if other people will be using your application, you would need to manage the DSNs on multiple machines.

Read data from a SQL Server database in Visual Basic in MS Access

What's the best way to read data from a SQL Server database in VB from MS Access?
I have a SQL Server database set up and I'm doing the forms etc. in Access. Now I need to read a boolean value and do so in VB.
I'd like to do that without opening a new connection. Is that somehow possible?
You can run a query against a linked table. As far as I know, the usual choice for Boolean in SQL Server is bit:
SELECT dbo_Table1.ID, dbo_Table1.ABoolean
FROM dbo_Table1
WHERE dbo_Table1.ABoolean=True
In MS Access, True displays as -1 and in SQL Server it displays as 1.
The query can also be run through VBA, if that is what you need to do.
Dim rs As DAO.Recordset
Set rs = CurrentDb.OpenRecordset("dbo_table_1")
Do While Not rs.EOF
If rs!ABoolean = True Then
Debug.Print rs!ID
End If
rs.MoveNext
Loop
Or
sSQL = "SELECT ID, ABoolean FROM dbo_table_1 WHERE ABoolean=True"
Set rs = CurrentDb.OpenRecordset(sSQL)
rs.MoveLast
Debug.Print rs.RecordCount
Or
Debug.Print DLookup("Aboolean", "dbo_table_1", "ID=37")

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