[kovidgoyal]

No, calibre is based on sqlite3. Try this little experiment. Download the official sqlite3 binary. Run

sqlite3 :memory:
SQLite version 3.39.2 2022-07-21 15:24:47
Enter ".help" for usage hints.
sqlite> CREATE TABLE authors ( id   INTEGER PRIMARY KEY,
                              name TEXT NOT NULL COLLATE NOCASE,
                              sort TEXT COLLATE NOCASE,
                              link TEXT NOT NULL DEFAULT "",
                              UNIQUE(name)
                             );
sqlite> .schema
CREATE TABLE authors ( id   INTEGER PRIMARY KEY,
                              name TEXT NOT NULL COLLATE NOCASE,
                              sort TEXT COLLATE NOCASE,
                              link TEXT NOT NULL DEFAULT "",
                              UNIQUE(name)
                             );
sqlite>

Astounding!! There are types in that table and sqlite3 didnt complain!! Who'da thunk it!!