Using Excel as front end to Access database (with VBA)
I am building a small application for a friend and they'd like to be able to use Excel as the front end. (the UI will basically be userforms in Excel). They have a bunch of data in Excel that they would like to be able to query but I do not want to use excel as a database as I don't think it is fit for that purpose and am considering using Access. [BTW, I know Access has its shortcomings but there is zero budget available and Access already on friend's PC]
To summarise, I am considering dumping a bunch of data into Access and then using Excel as a front end to query the database and display results in a userform style environment.
Questions:
- How easy is it to link to Access from Excel using ADO / DAO? Is it quite limited in terms of functionality or can I get creative?
- Do I pay a performance penalty (vs.using forms in Access as the UI)?
- Assuming that the database will always be updated using ADO / DAO commands from within Excel VBA, does that mean I can have multiple Excel users using that one single Access database and not run into any concurrency issues etc.?
- Any other things I should be aware of?
I have strong Excel VBA skills and think I can overcome Access VBA quite quickly but never really done Excel / Access link before. I could shoehorn the data into Excel and use as a quasi-database but that just seems more pain than it is worth (and not a robust long term solution)
Any advice appreciated.
Alex
Answer
I'm sure you'll get a ton of "don't do this" answers, and I must say, there is good reason. This isn't an ideal solution....
That being said, I've gone down this road (and similar ones) before, mostly because the job specified it as a hard requirement and I couldn't talk around it.
Here are a few things to consider with this:
How easy is it to link to Access from Excel using ADO / DAO? Is it quite limited in terms of functionality or can I get creative?
It's fairly straitforward. You're more limited than you would be doing things using other tools, since VBA and Excel forms is a bit more limiting than most full programming languages, but there isn't anything that will be a show stopper. It works - sometimes its a bit ugly, but it does work. In my last company, I often had to do this - and occasionally was pulling data from Access and Oracle via VBA in Excel.
Do I pay a performance penalty (vs.using forms in Access as the UI)?
My experience is that there is definitely a perf. penalty in doing this. I never cared (in my use case, things were small enough that it was reasonable), but going Excel<->Access is a lot slower than just working in Access directly. Part of it depends on what you want to do....
In my case, the thing that seemed to be the absolute slowest (and most painful) was trying to fill in Excel spreadsheets based on Access data. This wasn't fun, and was often very slow. If you have to go down this road, make sure to do everything with Excel hidden/invisible, or the redrawing will absolutely kill you.
Assuming that the database will always be updated using ADO / DAO commands from within Excel VBA, does that mean I can have multiple Excel users using that one single Access database and not run into any concurrency issues etc.?
You're pretty much using Excel as a client - the same way you would use a WinForms application or any other tool. The ADO/DAO clients for Access are pretty good, so you probably won't run into any concurrency issues.
That being said, Access does NOT scale well. This works great if you have 2 or 3 (or even 10) users. If you are going to have 100, you'll probably run into problems. Also, I tended to find that Access needed regular maintenance in order to not have corruption issues. Regular backups of the Access DB are a must. Compacting the access database on a regular basis will help prevent database corruption, in my experience.
Any other things I should be aware of?
You're doing this the hard way. Using Excel to hit Access is going to be a lot more work than just using Access directly.
I'd recommend looking into the Access VBA API - most of it is the same as Excel, so you'll have a small learning curve. The parts that are different just make this easier. You'll also have all of the advantages of Access reporting and Forms, which are much more data-oriented than the ones in Excel. The reporting can be great for things like this, and having the Macros and Reports will make life easier in the long run. If the user's going to be using forms to manage everything, doing the forms in Access will be very, very similar to doing them in Excel, and will look nearly identical, but will make everything faster and smoother.