Comparison documents

Applies to: AdeptSQL Diff version 1.90 and higher

The Diff treats connection parameters and other comparison-specific settings as a 'project' or 'document' that can be saved to a file and re-opened later. Such comparison document can also be specified at startup in the command line, along with various command-line parameters. The default file extention for comparison documents is .ASQ and the Diff registers itself during its installation as the default application to open .ASQ files.

All usual operations with comparison documents (New/Open/Save/SaveAs) can be found, not surprizingly, in the Diff's File menu. The New, Open and Save commands are also available via toolbar buttons.

The Open/Save/Save As commands work as usual and hardly need any explanation, but the New command does. In previous versions, the New Comparison simply displayed the connection panel and did nothing else. In this version, when you choose "New comparison", you are presented with a dialog box asking if you want to clear the current comparison settings first. If you answer "No", the connection panel with the current connection parameters gets displayed, just like before. If you answer "Yes", the current comparison is closed and all current project information cleared. This is more like the classic "New document" command.

The following information is saved in an .ASQ file:

• Connection strings for each of the 2 databases being compared (or a single connection string if there is just one database being explored). The password(s) will or will not be saved with the connection string(s) depending on the "Allow saving password" checkbox in the connection dialog (see the note below).

• Any schema-reading filters, telling the Diff to ignore certain schema objects when reading these particular database(s). [In version 1.90, no such filters are implemented yet].

• A list of renaming links, if any such links exist. You can use renaming commands to tell the Diff that, for example, table Buyers in the first database is equivalent and should be compared to table Customers in the second one, etc. Obviously, such associations must not disappear when you re-compare the databases, so they are kept with the project.

• The current layout of the schema tree. The Diff remembers which branches of the tree were expanded and which were collapsed, it also keeps the last selected item. When you re-load the comparison, the schema tree will look much the same as it looked when you were last saving the project.

• Any DataDiff settings specific to these two databases (such as whether the server-side scripting should be used).

• Complete set of table-wise and column-wise DataDiff settings for each pair of tables you have compared in DataDiff. This includes any filter conditions, options, lists of ignored and key columns, and so on.

Note on passwords: If you use SQL Server-level authorization, and you want to re-run the comparison later without having to enter the password every time, you can tell the Diff to save password(s) with the comparison project. Obviously, there is a security risk involved, so the program will ask you for confirmation before saving. Although the Diff doesn't keep the password in plain-text, it doesn't use a secure encryption either, instead applying a simple garbling algorithm. Moreover, even without un-garbling the password, anybody can open an .ASQ file on any machine with AdeptSQL Diff and therefore get access to your valuable databases.

Therefore, it may be much safer to either use Windows-level authorisation for your databases (so that no passwords need ever be saved or specified at all), or not to save the password with a comparison project.

Comparison document format. An AdeptSQL Diff comparison document is a text file similar to an .INI file. Major pieces of information (listed above) are [Sections] within this file, individual options are "Name=Value" lines under their respective sections. There should be no need for you to edit the .ASQ files manually, so no detailed description of the format is provided here. However, in an unlikely case you do need such information, it should be easy to find by studying a sample .ASQ file.