How to Decompile an Access Application Or How to do a Full Fresh Compile

[TheSmileyCoder]

Introduction:

I have always found Access ability to do handle code-changes while in break mode quite astounding. However there is a very real risk of corrupt code being stored in your database when you edit code while in break mode. Access doesn't really clean up the old bits of compiled code, and sometimes it seems to get confused about which bit of pre-compiled code it should use.


If you suddenly find that your application suddenly and for no good reason starts to error on code that was previously working without a hitch, there is a good chance that a bit of spring cleaning will fix it.

How to spring clean your application
Access has a command line option called /decompile. This will toss away all your compiled code (not the source code, don't worry, simply the precompiled version of the code). This is similar to the Compact And Repair removing cached versions of tables and queries, only this does it for form modules and stand-alone modules.

1. First ensure that all access applications are closed.
2. Ensure that you have done a backup of your application.
   Click Start->Run and then type:
3. 1. Access 2010: C:\Program Files\Microsoft Office\Office14\MSACCESS.EXE /decompile
      Note that the path will vary depending on your OS and your version of access
4. From the access window, open up your application while holding down shift.
5. Alt-F11, then choose from the menu: Debug->Compile (This will compile all modules)
6. You may want to finish off with a Compact and Repair, though I don't really know if its necesarry at this point.
7. Close and reoopen access to turn off the decompile option.

Your application should hopefully now be ready to run "normally" again.

[NeoPa]

Simple, but can be very important when a database is causing trouble in a project. Thanks for this Smiley :-)

[jonnycakes]

Yes, thank you for this! Very easy to understand even as a novice. Can this process do any harm to the database? I understand that I should make a backup, but what are the risks involved?

I'm considering using this method, but I'm not sure what I should be testing to ensure nothing went wrong.

Thanks again.

[TheSmileyCoder]

@NeoPa
Your welcome

@Jonnycakes
Your welcome
To the best of my knowledge the decompile is harmless.

The compact and repair has been known to sometimes cause a database to be left in a state where it can no longer be opened, allthough I can not recall if it has ever happened to me.

[twinnyfo]

Smiley,

I have had the Compact and Repair hang on me before, and one time, when I ran it, it STRIPPED all off the code out of every module!! :-o Fortunately I had a backup....

However, this functiondoes appear to do different things to the database. Do you find that this also reduces the size of the final product? Or is the size difference insignificant?

[TheSmileyCoder]

I suppose it ought to reduce the size, but whether its significant or not I haven't really looked at.

[NeoPa]

It should only make a difference if Access had previously managed to get something wrong. In that case, it would change the size to what it should have been had there been no error in the first place. How much of a difference that would make, if any, is the length of a piece of string. For those non-English out there that means it can be any length.

[NeoPa]

This saved my life today, with a client that had a corrupted BE.

System in use continuously all through the working day and quite a lot outside of that too. I managed to get them working again within a relatively short time using this technique. Even then - most of the delay was getting them all to come out properly.

Long story short - this was a life-saver.