We generate a poor error message when `infer_schema!` is used on an empty database

[sgrif]

Steps to reproduce:

Use infer_schema!("empty_database_file.sqlite3");

This should generate no code, but instead it errors out with "unexpected end of macro invocation".

[sgrif]

It looks like infer_schema! actually finishes fine, but the code it generates is allow_tables_to_appear_in_same_query!() which doesn't have a matcher for zero tokens

[bitemyapp]

Is "empty database" inclusive of "wrong filepath?" That was what happened in my case.

[sgrif]

Yes, pointing to a file which doesn't exist would cause SQLite to create a new database at that location, which would be empty.

[sgrif]

This was resolved.