DETACH
This statement detaches an additional database connection previously attached using the ATTACH statement. When not in shared cache mode, it is possible to have the same database file attached multiple times using different names, and detaching one connection to a file will leave the others intact.
In shared cache mode, attempting to attach the same database file more than once results in an error.
SQLite is in the Public Domain.
https://sqlite.org/lang_detach.html