Summary

Synopsis

The Schema Version field is found in SQL Scripts View | General Tab and can be used to version SQL scripts so they are run only when needed. The schema is specific to each SQL script.

Discussion

InstallShield creates an InstallShield table in the target database in order to maintain the schema version. This table holds the highest schema version from any executed SQL scripts in the last SQL connection. The schema version is used when making additional connections in the same project or during an upgrade to decide whether to run various SQL scripts. Here is an example:

Connection A
+ Script 1 (4.0)
+ Script 2 (3.0)

Connection B
+ Script 3 (4.1)
+ Script 4 (3.1)

InstallShield gets the current schema from the database each time a connection is opened and stores the highest version each time a connection is closed. The behavior of the preceding scripts is as follows assuming that both Connection A and B target the database named TestDB on TESTSQL2K server, and TestDB currently has schema version equal to 2.0:

1. Open Connection A (connecting to TestDB on TESTSQL2K).

2. Retrieve the current schema from TestDB = 2.0.

3. Run Script 1 (4.0 > 2.0).

4. Run Script 2 (3.0 > 2.0).

5. Write 4.0 to TestDB as the current schema.

6. Close Connection A.

7. Open Connection B (connecting to TestDB on TESTSQL2K).

8. Retrieve the current schema from TestDB = 4.0.

9. Run Script 3 (4.1 > 4.0).

10. Do not run Script 4 (3.1 < 4.0).

11. Write 4.1 to TestDB as the current schema.

12. Close Connection B.

Additional Information

The SQL script always executes if no schema version is specified.

The SQL schema data is not automatically removed from the database upon uninstallation. It is necessary to run a custom script upon uninstallation to remove the version number or drop the table if you want the installation to roll back the changes.

For more information on the Schema Version field, see Flexera Software Helpnet topic General Tab.