wcl...@gfs-hofheim.de wrote: > What I would really like to be able to do would be to cache objects > returned by sqlite3_column_value(...) and process them later, even after > the statement that generated them is finalised
You can't. The only thing you can reliably do with the result of sqlite3_column_value is to pass it to sqlite3_bind_value or sqlite3_result_value. Further, that sqlite_value pointer is only valid while the statement is live and positioned at the same row: any call to sqlite3_step, sqlite3_reset or sqlite3_finalize invalidates it. You will have to call sqlite3_column_type, then the appropriate sqlite3_column_*. If the type is string or blob, you would also need to make a copy of the actual data if you want it available for later processing. > I realise that I could cache them in their final form (e.g. as integer, > string, whatever in some form of union or struct), but at the point the > statement runs and the row is being read, it may not be fully determined > what form the output might be -- e.g. in the database it might be stored > as integer, but required as float or string, etc. and for this to be known > much later. Since sqlite provides such a useful means of "converting" > types through the sqlite_value* functions, I would really like to be able > to use these. Well, too bad. > Looking through the documentation, I can't seem to find an api function > that converts "unprotected" value to objects to "protected" ones. "Protected" means "a mutex is held while the value is outstanding". If such a hypothetical API existed, it would mean you could instruct SQLite to hold a mutex for an indefinite period of time, thus blocking all other activity on the connection. I doubt you actually want that. Igor Tandetnik _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
