The [CREATE INDEX syntax](https://sqlite.org/lang_createindex.html) provides no way to specify such creation. Your attempt failed to compile. It is not possible and I submit that it never should be. If that was possible, the index would easily become out of date and lead to bad results when used. In general, SQLite allows queries involving multiple schema (or databases), but does not support ostensibly permanent linkages such as you want(ed.) As for the old DBase days: Did its authors ever add referential integrity enforcement to it? Before it entered the dustbin of history?