I have this problem: I'm using a SQL Server 2008R2 backend and MS Access 2000 frontend where some tables are connected via ODBC.
Following Structure (Tables all on SQL-Server):
Import (not connected to Access)
Products (connected via ODBC to Access)
Pricing (connected via ODBC to Access)
I want to fill the Pricing table automatically with some data from Products and Import. This is supposed to run as a SQL Agent job with a T-SQL script.
I want to insert the data from "Products" with following command:
INSERT INTO Pricing (Productnr, Manufacturernr)
(SELECT Productnr, Manufacturernr
FROM Products
WHERE Valid = 1
AND Productnr NOT IN (SELECT Productnr FROM Pricing ));
Right after that the inserted rows are locked for Access, I can't change anything. If I execute sql queries with SQL Server Management Suite or if i start queries as SQL Agent jobs everything works fine.
Why are the rows locked in ms access after the query ran (even if it finished successfully)? and how can I unlock them or make it unlock itself right after the query/job ran?
Thanks
When SQL Server inserts new rows, those new rows are in fact exclusively locked to prevent other transactions from reading or manipulating them - that's by design, and it's a good thing! And it's something you cannot change - you cannot insert without those locks.
You can unlock them by committing the transaction that they're being inserted under - once they're committed to SQL Server, you can access them again normally.
The error message i get says, that the dataset has been changed by another user and if i save it, i would undo the changes of the other user. (and asks me for copying into clipboard).
This is different from "locked", and completely normal.
If you have a ODBC linked table (or form based on the table) open, and change data in the backend, Access doesn't know about the change.
You need to do a full requery (Shift+F9) in Access to reload the data, afterwards all records can be edited again.
Got the solution for my Problem now.
I had to add a timestamp row into the pricing table, so access could recognize the change.
Access loads the data into the front end when the table is first accessed. If something in the backend changes the data, you need Access to refresh it first, before you can edit it from the front end (or see the changes).
Do this by (in Access) by closing and reopening the table, or switching to the table and pressing shift-F9 as Andre suggested, or programmatically using a requery statement. You must requery, not refresh, for it to release the locks and register the changes made in SQL.
Related
I am attempting to "sync" data from a read-only ODBC MySQL server to Access 2016. I need to move the data into Access so that I can more easily manipulate and create better customized reports.
I have linked the data tables between Access and MySQL, however I cannot get the data in these tables to automatically refresh. I must go into Access and hit "Refresh All".
What I'm looking to do is update all of my open tables in Access once nightly so that each morning the data used to build these reports is new. Currently if I leave these tables all evening, when I get in the next morning I must hit "Refresh-All" for Access to go retrieve the most recent data.
Any ideas?
The data in linked tables is automatically refreshed by access when you attempt to read them. You can do that by displaying a datasheet view of the database, or by a form where the linked table is the data source. Beware, we have had problems which tables with lots of records being the source for drop down lists, having the database locked.
Access only does this properly (and at speed) if either the underlying table has a unique clustered index, or after having linked the tables you create an index in access.
If you want to create a copy that you can manipulate (such as write to) and the underlying tables are read only, then you will have to create matching unlinked tables and execute some form of copy sql and appropriate points in your application.
I have 2 table, one is local named 'Client' and other is a linked table to MySQL DB in my web-server named 'ClientSql'.
When I insert data into the table Client, I want it to be insert into clientSql too. I try it with data macro (after insert), but it shows me an error saying
It's not possible in linked tables.
I have tried to create an append query successfully, and it works, but it just works if I execute it manually. My question is:
Is it possible to call it from a data macro? if is possible, can you show me how? If not, can you point me to a solution?
I'm not sure why you should be able to do it manually, but not via a macro. According to this link
http://dev.mysql.com/doc/connector-odbc/en/connector-odbc-examples-tools-with-access-linked-tables.html
you should be able to do it either way.
Another thought is to eliminate the local access client table and have the access program update the mySql table directly. However, if another program is accessing the client table at the same time, this could become tricky due to multi-user and locking situations.
I have this project that would require users to check in/out through a finger print reader ZK SF200.
The system that I am building needs to fetch new data that is added into this machine's database which unfortunately is a MS Access mdb file.
In my limited experience in MS Access databases, I managed to link this file to my MySql database table which allows me to manually do the insert from MS Access.
All I want to do now is to create some form of trigger that would add data to my MySql database when new rows are inserted into the MS Access table.
This problem would have been solved if the file type was .accdb because we can use After Insert events however it is an mbd type so those are not supported.
Any idea on how I can solve this matter ?
As a final note: I am willing to change DBMS in case MySql is the obstacle here. Would creating a linked server or doing sql server replication through mssql 2008 r2 work ?
EDIT: I need to insert data to MySql table because I have a trigger implemented there which does its side of logical manipulation of the data (ex: Increment the number of visits for the customer, check if customer subscription has expired or not and update the customer status accordingly)
Thank you.
Linking a table in MS-Access to the ODBC source is probably an answer for you. The table in MS-Access will be more like a view on the source table. Any DML operation (INSERT, UPDATE, DELETE) will be synced immediately with the source database. You will not need any trigger, which is not available in MS-Access (unless some VBA expert knows a solution).
The Linked table technology is default available for SQL-server, but since it uses ODBC I quess you can use it with MySQL too.
I'm migrating the data from an Access database to SQL Server via the SQL Server Migration Assistant (SSMA). The Access application will continue to be used with the local tables converted to linked tables.
One continuous form hangs for 15 - 30 seconds when it's loading. It displays approximately 2000 records. When I looked in SQL Server Profiler to see what it was doing, it was making a separate call to the backend database for each record in the form. So the delay when the form opens is caused by the 2000-odd separate calls to the database.
This is amazingly inefficient. Is there any way to get Access to make a single call to the backend database and retrieve all the records at once?
I don't know if this is relevant but the Record Source for the form is a view in the SQL Server backend database, which is linked to via an Access linked table (so, hopefully, Access just sees it as a table, not a view). I needed an Instead Of trigger on the view in SQL Server, and a unique index on the linked table in Access, to allow the records to be updated via the form.
If the act of opening that continuous form really does generate ~2000 separate SQL queries (one for every row in the view) then that is unusual behaviour for Access interacting with a SQL Server linked "table". Under normal circumstances what takes place is:
Access submits a single query to return all of the Primary Key values for all rows in the table/view. This query may be filtered and/or sorted by other columns based on the Filter and Order By properties of the form. This gives Access a list of the key values for every row that might be displayed in the form, in the order in which they will appear.
Access then creates a SQL prepared statement using sp_prepexec to retrieve entire rows from the table/view ten (10) rows at a time. The first call looks something like this...
declare #p1 int
set #p1=4
exec sp_prepexec #p1 output,N'#P1 int,#P2 int,#P3 int,#P4 int,#P5 int,#P6 int,#P7 int,#P8 int,#P9 int,#P10 int',N'SELECT "ID","AgentName" FROM "dbo"."myTbl" WHERE "ID" = #P1 OR "ID" = #P2 OR "ID" = #P3 OR "ID" = #P4 OR "ID" = #P5 OR "ID" = #P6 OR "ID" = #P7 OR "ID" = #P8 OR "ID" = #P9 OR "ID" = #P10',358,359,360,361,362,363,364,365,366,367
select #p1
...and each subsequent call uses sp_execute, something like this
exec sp_execute 4,368,369,370,371,372,373,374,375,376,377
Access repeats those calls until it has retrieved enough rows to fill the current page of continuous forms. It then displays those forms immediately.
Once the forms have been displayed, Access will "pre-fetch" a couple of more batches of rows (10 rows each) in anticipation of the user hitting PgDn or starting to scroll down.
If the user clicks the "Last Record" button in the record navigator, Access again uses sp_prepexec and sp_execute to request enough 10-row batches to fill the last page of the form, and possibly pre-fetch another couple of batches in case the user decides to hit PgUp or start scrolling up.
So in your case if Access really is causing SQL Server to run individual queries for every single row in the view then there may be something particular about your SQL View that is causing it. You could test that by creating an Access linked table to a single SQL Table or a simple one-table SQL View, then use SQL Server Profiler to check if opening that linked table causes the same behaviour.
Turned out the problem was two aggregate fields. One field's Control Source was =Count(ID) and the other field's Control Source was =Sum(Total_Qty).
Clearing the control sources of those two fields allowed the form to open quickly. SQL Server Profiler shows it calling sp_execute, as Gord Thompson described, to retrieve seven batches of 10 rows at a time. Much quicker than making 2000 calls to retrieve one row at a time.
I've come across the same problem again but this time with a different cause. I'm including it here for completeness, to help anyone in a similar situation:
This time the underlying query was hanging and SQL Server Profiler showed the same behaviour as before, with Access making separate calls to the SQL Server database to bring back one record at a time, for every record in the query.
The cause turned out to be the ORDER BY clause in the query. I guess Access had to pull back all records in the linked table from SQL Server before being able to order them. Makes sense when I think of it. Although I don't know why Access doesn't just pull all records through at once, instead of getting the records one at a time.
I would try setting the Recordset Type to Snapshot (on the Data tab of the Form's property sheet and/or the property sheet of the query you are using for the form source)
I have a mySQL database that tracks our projects and drives our website's display of their info. For ease of updating the database I have set up an access database that used an ODBC connection (MySQL ODBC 5.1) to edit the data. It has been working just fine for the past few months with no hiccups.
However, last night users(2 of 3) experienced Write Conflict errors. The users could only Copy the changes to the Clipboard or Drop the changes. So thinking there is something wrong with the Access database I created a new access database, linked the tables through the ODBC connection, and still the issue occurred. I also deleted and recreated the ODBC connection, to no effect.
So where do I go from here? What could have caused this issue to crop up now, not when I was setting this up months ago?
There have been no changes to the database server, database or access database in the last week (+5 days).
We have made sure that only one instance of Access is attempting to effect the database.
All tables have a PK and a timestamp column.
We are not using any forms, just using the Table interface.
The server has not been updated, nor has the ODBC connection.
We are using Access 2007
Nothing is showing up in the server's error log when we try and update rows.
In general, all ODBC databases used from Access need to have PKs in all tables and timestamp fields in them that are updated each time the record is changed. Access uses this in bound forms for handling refreshes of the bound data and Jet uses them in in choosing how to tell the ODBC database what do update.
You may be able to get things to work with some tables without PK and timestamp, but I've found that it's best just to make sure that all your tables have them so you don't run into the problem (I never have any tables with no PK, of course).y
Make sure BIT columns have default values that are not NULL. Any records which have a BIT column set to NULL could get the Write Conflict error.