Hi i am working on access 2007-2013 application with DSN-less linked, the application is working perfectly, but when i shared it with other users i am getting the following error
Run-time error '3328' table is read-only
i tried to enable the active x component in the application under options then go to trust center, and check [Never show information about blocked content]
also i noticed that when one user open the application the other user get this message
Could not lock file
how can i solve this issue? i know i have to go to do something under options, but what?
thank you
Like #AVG said, you're going to need split architecture.
This has to components:
Back End
This is where all of your tables will be stored. It is just another Access database, without Forms/Queries/Reports/Modules.
Front End
This is where you are going to Link to your Back End, and this WILL contain Forms/Queries/Reports/Modules, and create linked tables as well.
You're going to distribute this Front End to all of your users to solve these concurrency issues you're facing (people are editing records/viewing data and others are trying to write to that table and do other things at the same time, which Access doesn't like).
The Back End needs to be in a location where everyone has access to it.
I think in your question what you're asking for, would be this, but splitting the front end and back end is by far the best route to go. Simply turning off the security checks Access has in place to protect your data isn't advised in the least. It also helps reduce bloat.
For disabling record locks : Click the top left Office Button, Click Options, Click Advances. Select No Locks.
I'm working on an access application in local.
I'd like to use this application on a local network on differents computers.
I heard that I could create a client side application and a server side access application, the clients are connected to the server just giving the server path to the client but I don't find how to do that.
Thanks for your help.
The best thing to do would be to split the database into a Front End and a Back End. You can do this manually, although there is actually a wizard within Access that will do it as well. The result is basically a "back end" with all the tables, and a "front end" with everything else (queries, forms, reports, macros and modules). All you have to do is link the tables in the back end to the front end, the same way you would link to any external data whether it be Access, SQL Server or what have you.
You can then distribute the front end to all your users, leaving your back end on a network. Just make sure you never move your back end, or your distributed front ends will not know where to find the data.
I split my DB and now when I try to change some information on a few queries, I can't access them. I have a front end and a back end and understand that I should make changes to queries/forms via the front end, but they are grayed out and inaccessible.
At this point, I tried unsplitting the DB (which I believe I did), but I still can't edit those queries or forms.
I can click on the query/form and see the result of it, but I can't get to design view to edit it.
I'm taking a shot in the dark and saying that in the process of splitting your database, you either created your front-end in an accdr or accde format (a runtime application). The purpose of this is that you shouldn't be able to open queries or forms or tables in design view on the front end. You can just open your database and save it again as an accdb file and continue as normal.
If you're having other problems with the linked tables, I suggest you open the Linked Table Manager and refresh the links (if you moved the backend file, this is necessary).
I would recommend trying to proceed as normal by using Shift Bypass just to be sure. ( Hold the shift key when you start the database. Then attempt to modify in design view).
If these fail, I would attempt to copy the queries and /or forms if possible and create new ones.
I have created an MS Access 2003 application, set up as a split front-end/back-end configuration, with a user group of about five people. The front end .mdb sits on a network file server, and it contains all the queries, forms, reports, and VBA code, plus links to all the tables in the back end .mdb and some links to ODBC data sources like an AS/400. The back end sits on the same network file server, and it just has the table data in it.
This was working well until I "went live" and my handful of users started coming up with enhancement requests, bug reports, etc. I have been rolling out new code by developing/testing in my own copy of the front-end .mdb in another network folder (which is linked to the same back-end .mdb), then posting my completed file in a "come-and-get-it" folder, alerting the users, and they go copy/paste the new front-end file to their own folders on the network. This way, each user can update their front end when they're at a 'stopping point' without having to boot everyone out at once.
I've found that when I'm developing now, sometimes Access becomes extremely slow. Like, when I am developing a form and attempt to click a drop-down on the properties box, the drop-down arrow will push in, but it will take a few seconds before the list of options appears. Or there's tons of lag in selecting & moving controls on a form. Or lots of keyboard lag.
Then, at other times, there's no lag at all.
I'm wondering if it's because I'm linked to the same back end as the other users. I did make a reasonable effort to set up the queries, forms, reports etc. with minimal record locking, if any at all, depending on the need. But I may have missed something, or perhaps there is some other performance issue I need to address.
But I'm wondering if there is an even better way for me to set up my own development back-end .mdb, so I can be testing my code on "safe" data instead of the same live data as the rest of the users. I'm afraid that it's only a matter of time before I corrupt some data, probably at the worst possible moment.
Obviously, I could just set up a separate back-end .mdb and manually reconfigure the table links in the front end every time, using the Linked Table Manager. But I'm hoping there is a more elegant solution than that.
And I'm wondering if there are any other performance issues I should be considering in this multi-user, split database configuration.
EDIT: I should have added that I'm stuck with MS Access (not MS-SQL or any other "real" back end); for more details see my comment to this post.
If all your users are sharing the front end, that's THE WRONG CONFIGURATION.
Each user should have an individual copy of the front end. Sharing a front end is guaranteed to lead to frequent corruption of the shared front end, as well as odd corruptions of forms and modules in the front end.
It's not clear to me how you could be developing in the same copy of the front end that the end users are using, since starting with A2000, that is prohibited (because of the "monolithic save model," where the entire VBA project is stored in a single BLOB field in a single record in one of the system tables).
I really don't think the problems are caused by using the production data (though it's likely not a good idea to develop against production data, as others have said). I think they are caused by poor coding practices and lack of maintainance of your front end code.
turn off COMPILE ON DEMAND in the VBE options.
make sure you require OPTION EXPLICIT.
compile your code frequently, after every few lines of code -- to make this easy, add the COMPILE button to your VBE toolbar (while I'm at it, I also add the CALL STACK button).
periodically make a backup of your front end and decompile and recompile the code. This is accomplished by launching Access with the /decompile switch, opening your front end, closing Access, opening your front end with Access (with the SHIFT key held down to bypass the startup code), then compacting the decompiled front end (with the SHIFT key held down), then compiling the whole project and compacting one last time. You should do this before any major code release.
A few other thoughts:
you don't say if it's a Windows server. Linux servers accessed over SAMBA have exhibited problems in the past (though some people swear by them and say they're vastly faster than Windows servers), and historically Novell servers have needed to have settings tweaked to enable Jet files to be reliably edited. There are also some settings (like OPLOCKS) that can be adjusted on a Windows server to make things work better.
store your Jet MDBs in shares with short paths. \Server\Data\MyProject\MyReallyLongFolderName\Access\Databases\ is going to be much slower reading data than \Server\Databases. This really makes a huge difference.
linked tables store metadata that can become outdated. There are two easy steps and one drastic one to be taken to fix it. First, compact the back end, and then compact the front end. That's the easy one. If that doesn't help, completely delete the links and recreate them from scratch.
you might also consider distributing an MDE to your end users instead of an MDB, as it cannot uncompile (which an MDB can).
see Tony Toews's Performance FAQ for other generalized performance information.
1) Relink Access tables from code
http://www.mvps.org/access/tables/tbl0009.htm
Once I'm ready to publish a new MDE to the users I relink the tables, make the MDE and copy the MDE to the server.
2) I specifically created the free Auto FE Updater utility so that I could make changes to the FE MDE as often as I wanted and be quite confident that the next time someone went to run the app that it would pull in the latest version. For more info on the errors or the Auto FE Updater utility see the free Auto FE Updater utility at http://www.granite.ab.ca/access/autofe.htm at my website to keep the FE on each PC up to date.
3) Now when working on site at a clients I make the updates to the table structure after hours when everyone is out of the system. See HOW TO: Detect User Idle Time or Inactivity in Access 2000 (Q210297) http://support.microsoft.com/?kbid=210297 ACC: How to Detect User Idle Time or Inactivity (Q128814) http://support.microsoft.com/?kbid=128814
However we found that the code which runs on the timer event must be disabled for the programmers. Otherwise weird things start happening when you're editing code.
Also print preview would sometimes not allow the users to run a menu item to export the report to Excel or others. So you had to right click on the Previewed report to get some type of internal focus back on the report so they could then export it. This was also helped by extending the timer to five minutes.
The downside to extending the timer to five minutes was if a person stays in the same form and at the same control for considerable parts of the day, ie someone doing the same inquiries, the routine didn't realize that they had actually done something. I'll be putting in some logic sometime to reset this timer whenever they do something in the program.
4) In reference to another person commenting about scripts and such to update the schema see Compare'Em http://home.gci.net/~mike-noel/CompareEM-LITE/CompareEM.htm. While it has its quirks it does create the VBA code to update tables, fields, indexes and relationships.
Use VBA to unlink and re-link your tables to the new target when switching from dev to prod. It's been to many years for me to remember the syntax--I just know the function was simple to write.
Or use MS-Access to talk to MS-Access through ODBC, or some other data connection that lives outside of the client mdb.
As with all file base databases, you will eventually run into problems with peak usage or when you go over a small magical number somewhere between 2 and 30.
Also, Access tends to corrupt frequently, so backup, compact and repair need to be done on an frequent basis. 3rd party tools used to exist to automate this task.
As far as performance goes, the data is being processed client side, so you might want to use something like netmeter to watch how much data is going over the wire. The same principle about indexing and avoiding table scans apply to file base dbs as well.
Many good suggestions from other people. Here's my 2 millicents worth. My backend data is on server accessed through a Drive mapping. In my case, the Y drive. Production users get the mapping through a login script using active directory. Then the following scenarios are easily done by batch file:
Develop against local computer by doing a subst command in a batch file
run reports against last nights data by pointing Y to the backup server (read only)
run reports against end of month data by pointing to the right directory
test against specialized scenarios by keeping a special directory
In my environment (average 5 simultaneous users, 1000's of rows, not 10,000's.) corruption has occurred, but it's rare and manageable. Only once in the last several years have we resorted to the previous days backup. We use SQL Server for our higher volume stuff, but it's not as convenient to develop against, probably because we don't have a SQL admin on site.
You might also find some of the answers to this question (how to extract schemas from access) to be useful as well. Once you've extracted a schema using one of the techniques that were suggested you gain a whole range of new options like the ability to use source control on the schemas, as well as being able to easily build "clean" testing environments.
Edit to respond to comment:
There's no easy way to source control an Access database in it's native format, but schema files are just text files like any other. Hence, you can check them in and out of the source control software of your choice for easy version control/rollbacks.
Or course, it relies on you having a series of scripts set up to re-build your database from the schema. Once you do, it's normally fairly trivial to create an option/alternative version that rebuilds it in a different location, allowing you to build test environments from any previous committed version of the schema. I hope that clarifies a bit!
If you want to update the back end MDB schema automatically when you release a new FE to the clients then see Compare'Em http://home.gci.net/~mike-noel/CompareEM-LITE/CompareEM.htm will happily generate the VBA code need to recreate an MDB. Or the code to create the differences between two MDBs so you can do a version upgrade of the already existing BE MDB. It's a bit quirky but works.
I use it all the time.
You need to understand that a shared mdb file for the data is not a robust solution. Microsoft would suggest that SQL Server or some other server based database would be a far better solution and would allow you to use the same access front end. The migration wizard would help you make the changeover if you wanted to go that way.
As another uses pointed out, corruption will occur. It is simply a question of how often, not if.
To understand the performance issues you need to understand that to the server the mdb file with the data in it is simply that, a file. Since no code runs on the server, the server does not understand transactions, record locking etc. It simply knows that there is a file that a bunch of people are trying to read and write simultaniously.
With a database system such as SQL Server, Oracle, DB2. MySQL etc. the database program runs on the server and looks to the server like a single program accessing the database file. It is the database program (running on the server) that handles record locking, transactions, concurrency, logging, data backup/recovery and all the other nice things one wants from a database.
Since a database program designed to run on the server is designed to do that and only that, it can do it far better and more efficently that a program like Access reading an writing a shared file (mdb).
There are two rules for developing against live data
The first rule is . . . never develop
against live data. Not ever.
The second rule is . . .never develop
against live data. Not ever.
You can programatically change the bindings for linked tables, so you can write a macro to change your links when you're deploying a new version.
The application is slow because it's MS Access, and it doesn't like many concurrent users (where many is any number > 1).
I've created a database in access 2007 that needs to be used by 3 users. I'm stuck because I don't know whether to place a copy on each users' computer or to place it on their SQL server. Placing it on the server would mean one access point which is desirable for data consistency but I don't know whether I need ActiveX. Don't know how to use it either. If I place it one each computer how do I work around the master file updates? Can somebody please break it all down, I'm a NEWBIE!!
Your question seems rather confused to me. You mention a SQL Server, but you don't say your application uses SQL Server for its data storage.
Thus, I can only assume that you have a single MDB or ACCDB file with your data tables and forms and reports all in the one file.
The only proper way to distribute this app is:
split it into front end (forms/reports/etc.) with linked tables that point to the back end (data tables only).
place the back end on your file server and relink your tables to point to the new location of the back end.
give a copy of the front end to each of the 3 users, who will run it from their desktop computers. If you're concerned about distributing changes to the front end, something like Tony Toews's front-end updater is very useful.
Others have jumped in to say that you should put the data in SQL Server, but most 3-user Access apps don't need the power of SQL Server. If you're not given administrative permissions on your SQL Server, it could be quite difficult to continue to alter your application's database.
On the other hand, if your database is going to grow to 1GB or more, or if you have strict security requirements, or if the data in your database is so important as to need completely failproof backups, then SQL Server would be a reasonable data store.
For most homegrown apps, not so much.
The "best" way I've worked this out is using Linked Tables in Access to go to SQL Server (since you stated you have that..?).
Using access as a front end in this scenario isn't the best thing you can do, but with 2007, it's a bit better than if you were a few versions back. Check out this article for info on linking Access into SqlServer:
Import or link to SQL Server data
One easy way is to use the EQL Data plugin: http://eqldata.com
That way you can give a copy of the database to each user, but users can sync the database with other users whenever they want. You can also access your tables and queries on the web.