View Differences Between Two Databases

The VBScript file WiDiffDb.vbs is provided in the Windows SDK Components for Windows Installer Developers. This sample script generates a temporary transform file between two Windows Installer databases and displays the transform.

The sample demonstrates the use of:

• OpenDatabase method (Installer Object)
• LastErrorRecord method of the Installer object
• OpenView method
• SummaryInformation property (Database Object)
• GenerateTransform method
• ApplyTransform method
• Database object
• Fetch method of the View object
• IsNull property
• StringData property of the Record object
• _TransformView table

Using this sample requires the CScript.exe version of Windows Script Host. To use CScript.exe to run this sample, type a command at the command prompt using the following syntax. Help is displayed if the first argument is /? or if too few arguments are specified. To redirect the output to a file, end the command line with VBS > [path to file]. The sample returns a value of 0 for success, 1 if help is invoked, and 2 if the script fails.

cscript WiDiffDb.vbs [path to original database][path to revised database]

Specify the path to the original Windows Installer database. Specify the path to the revised database. The sample script will display the transform.

For additional scripting examples, see Windows Installer Scripting Examples. For sample utilities that do not require Windows Script Host, see Windows Installer Development Tools.