On 7/11/17, Jens Alfke <j...@mooseyard.com> wrote: > I’m using FTS4, and queries involving a single MATCH expression work fine. > But if there are two MATCH expressions, the queries generated by my code > fail to compile, with an error "unable to use function MATCH in the > requested context”. Can someone explain what’s going wrong? >
While the query planner is processing the WHERE clause, it passes various terms down to FTS4 and asks "can you deal with this?" Normally, FTS4 will answer "yes" to a MATCH operator and take full responsibility for it, so that the SQLite core does not do any more with it. But in the specific query you have, FTS4 is unable to handle the MATCH function and so it answers "no". Or, maybe due to the OR clause, the query planner is not able to factor out the MATCH function and so it never even asks. I'm not sure which, but for whatever reason, FTS4 did not take responsibility for handling the MATCH operator. That means that the MATCH operator remained as the responsibility of the SQLite core. But the core has no idea what the MATCH operator is suppose to do. So it implements the MATCH operator using the sqlite3InvalidFunction() functions (https://www.sqlite.org/src/artifact/899d8f02?ln=748-768) and that function throws an error, by design. -- D. Richard Hipp d...@sqlite.org _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
