What is AccdbMerge?

AccdbMerge is an easy to use diff & merge tool for Microsoft Access *.mdb and *.accdb files. This tool allows to compare and import/export database objects and data between two files. AccdbMerge can run in two modes - basic free version described below on this page, and paid Pro mode that provides extended functionality and overcomes limitations of the free version.

Free version allows to compare unprotected files, compare and merge most of the application objects such as forms, queries or modules. It also provides basic data diff and merge facilities, allowing to compare table contents, merge the whole records or only required columns for chosen records.

AccdbMerge Pro has a number of significant functional improvements, such as batch data diff, protected and compiled files support, ability to merge table structure, indexes and relationships and more. In addition it has a lot of small nice refinements that will make your work much more productive. See the full list of AccdbMerge Pro advantages

Here is the quick video introduction to the AccdbMerge - by example of the Pro, however, most of the core features described in this video are available in the Free version:


How to use it?

This section describes how to use the free version - all these instructions are applicable to the Pro version as well. Just download, install and run. After choosing the free license you will get to the main Project tab:
Click on toolbar "Open File(s)" button or "Load file.." links to load required files:
You will get some kind of summary about database objects:
Using "total/new/changed" links you can navigate to required object type, for example to Modules:
On this screen using toolbar, you can:
- observe all objects, or only new, changed, or both new and changed,
- select multiple objects for further merge action, or you can select each line separately without toolbar,
- "Merge to left"/"Merge to right" buttons can be used to export/import selected objects. Each time you export/import objects, AccdbMerge will create a backup of chaged datagase in the same folder, with the same file name suffixed by timestamp (e.g. "db1_20120109092025.accdb"). 
From this screen you can navigate to some particular object: 
For text comparison there are options to ingore case and whitespaces.
AccdbMerge also allows to diff and merge table data. Navigating from Project -> Tables you will see  button - "Сompare data (all records)" for each table, which will open table diff window. If you have a lot of unchanged records and you need only to review changed - you can use  button - "Compare data (only new or changed records)". The same way as for objects list you can switch to all/new/changed records. Table diff window will indicate new/missed/changed records and missed fields, for changed records it will highlight fields with updated values:

Here you can merge data from one file to another. Mark records and fields that needs to be merged and use toolbar merge buttons. Toolbar selection buttons can be used for batch selection update.
Important notice! Data merge will not create backup of your data, so please be sure that you made a backup of the data that you are going to merge. You will see appropriate dialog with this warning.
Another useful feature is search for text across all project object definitions (but not across the data). This can be very helpful for example if you want to find all references to some particular field in all queries, forms and reports:
One more handy feature is an ability to compare queries SQL text in indented view. Usually Access query generator generates quite messy SQL, putting everything in a couple lines of text, doesn't matter how many tables being joined, or how many fields selected. This SQL is very hard to read and it is more hard to compare. Navigating from Project -> Queries you will see  button ("Compare indented") for each query, which will open diff window with indented query text:

System requirements:

- Microsoft Access 2007/2010/2013/2016
- Microsoft .NET Framework 4 Client Profile (required only for Windows XP/Vista/7, not required for Windows 8/8.1/10)  
- It may be necessary to install Microsoft Access Database Engine 2010 Redistributable from Microsoft (file "AccessDatabaseEngine.exe", not x64 version) to make data diff work properly on Windows x64


Author will be very happy if someone will find this program helpful. If you have any suggestions or bug reports, please write to support@accdbmerge.net.