A SchemaRev object contains information about a single schema revision, including information about its packages.
Schema revisions identify a particular version of a schema. You use schema revisions when creating and updating databases.
To set the schema revision of a new database, create the database, then call the database object's SetInitialSchemaRev method.
To change the schema revision of an existing database, call the Upgrade method of the Database object.
To discover which packages and package revisions apply to the current user database, use the GetEnabledPackageRevs and the GetEnabledEntityDefs methods.