On 9/4/18, Brian Vincent <bra...@gmail.com> wrote: > Hi, I'm currently writing a Go sqlite package, go-sqlite-lite. I think it > provides a good "pure" SQLite experience with Go. > > If I want to make sure that the sqlite3_column_* functions never provide a > false answer due to an error condition, like a memolry allocation error, > how should I go about that? The documentation seems inconsistent here. > > The documentation about sqlite3_column_*: > >> If a memory allocation error occurs during the evaluation of any of these > routines, a default value is returned. The default value is either the > integer 0, the floating point number 0.0, or a NULL pointer. Subsequent > calls to sqlite3_errcode() will return SQLITE_NOMEM. > > The documentation about sqlite3_errcode(): > >> If the most recent sqlite3_* API call associated with database connection > D failed, then the sqlite3_errcode(D) interface returns the numeric result > code or extended result code for that API call. If the most recent API call > was successful, then the return value from sqlite3_errcode() is undefined. > The sqlite3_extended_errcode() interface is the same except that it always > returns the extended result code even when extended result codes are > disabled. > > 1. How can I check the error code if I'm unsure if the column function was > successful or not? If it was successful, then the error code is undefined.
Just call sqlite3_errcode(). It will return SQLITE_OK if the sqlite3_column function was successful. If sqlite3_errorcode() returns something other than SQLITE_OK, then some recent API failed. It might not have been the sqlite3_column function, but it is still a failures, so just go with it. > 2. Is SQLITE_NOMEM the only error code possible for the sqlite3_column_* > functions? SQLITE_RANGE if you provide an invalid column number. SQLITE_MISUSE if the prepared statement has been reset or finalized. That is all in the current implementation, but new error codes might be added in the future. > 3. Is it possible for every single one of the sqlite3_column_* functions > to fail in this manner? I think only the routines that returns TEXT and BLOB use malloc() in the current implementation. That might change in the future though. -- 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
