Quick answer:
just use Activity.name.contains('Physics')
Depending on the database backend you're using you'll want to pick the right "wildcard". Postgresql and MySQL use "%", but for Sqlite if you're performing a LIKE
query you will actually want to use "*" (although for ILIKE it is "%", confusing).
I'm going to guess you're using SQLite since the above query is failing, so to recap, with SQLite if you want case-sensitive partial-string matching: Activity.name % "*Physics*"
, and for case-insensitive: Activity.name ** "%Physics%"
.