Obtaining a Database Handle

Before working with a database you must first obtain a handle to it.

To access information about an installer database

1. Obtain a handle to the database in one of two ways:
   • If an installation is in progress, get a handle to the active database by calling the MsiGetActiveDatabase function.
   • If an installation is not in progress, open any specified database by calling the MsiOpenDatabase function.
2. After the database has been opened, you can call functions to obtain information about the database or to manipulate the database.
   • Create a View object and specify a SQL query of the open database by calling the MsiDatabaseOpenView function.
   • Obtain a record that contains all primary keys of a specified table in the open database by calling the MsiDatabaseGetPrimaryKeys function.
   • Check the current state of an open database by calling the MsiGetDatabaseState function. With the MsiGetDatabaseState function, you can determine the read/write status for a database or if the handle is valid.