SQL Scripts to run only on first time install

[tcom36]

I have an InstallScript MSI project with some SQL scripts under the Server Configuration->Sql Scripts view.

Some of these scripts should only be called on the first install. I checked on these scripts the "Run Script During Install", but it gets also called on repair or update.

Is there any way to make them execute only on first install?

I tried to set a property OnFirstUIBefore:

MsiSetProperty(ISMSI_HANDLE, "MYPROJECT_FIRST_INSTALL", "first");

and use it under "Specify a Conditional Statement", but this statement does not seem to be evalutated properly.

Any idea?