Re: VTable Column Affinity Question and Change Request
Jens Alfke <jens-mAcipnqRhZf2eFz/[email protected]>
| Newsgroups | gmane.comp.db.sqlite.general |
|---|---|
| Message-ID | <[email protected]> |
> On Feb 5, 2020, at 9:58 AM, Keith Medcalf <[email protected]> wrote: > > It seems that "column affinities" are not respected in Virtual Table implementations -- that is the value that is returned is the datatype provided by the the vtab_cursor sqlite3_result_* function and the "column affinity" from the vtab declaration is not applied. The vtab implementation is responsible for generating the CREATE TABLE statement and passing it to sqlite3_declare_vtab(). It’s also responsible for returning column values. So I think the assumption is that it’s up to the implementation to be self-consistent, i.e. returning column values that match the declaration. I haven’t used the CSV vtable. It looks as though its CREATE VIRTUAL TABLE statement takes a ‘schema’ parameter containing the SQL table declaration, that it then passes straight through to sqlite3_declare_vtab(). It probably doesn’t parse that declaration or figure out from it what the declared types of the columns are. In other words this looks like a limitation of the CSV implementation, which is perhaps unusual in that it is not in control of the table schema it declares. —Jens _______________________________________________ sqlite-users mailing list [email protected] http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users