If you have 4 set clauses, the those 4 fields will be updated with the same values for all the rows matching the where clause with just a single call to sqlite3_step().
If you actually want to update only 1 of the fields in 1 record, then you must bind the current values (which are unknown and need to be determined first) of the other fields and make sure that your where clause matches only the 1 intended record. -----Ursprüngliche Nachricht----- Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im Auftrag von ghalwasi Gesendet: Montag, 11. September 2017 15:02 An: sqlite-users@mailinglists.sqlite.org Betreff: Re: [sqlite] [EXTERNAL] Performance impact of UPDATEing multiple columns vs few columns hi Darko, >If you're preparing that statement more than once then you are wasting time, there's no reason whatsoever to do it. You're also wasting time if you make a bind call to set any column that hasn't changed since the last time you executed the statement. >The entire row is rewritten when updating so the most efficient way to >do it is to call sqlite3_prepare_v2 once, then bind any columns that have changed, call sqlite3_step to execute the statement, then call sqlite3_reset to reuse the statement, then go back to binding any columns that have changed and repeat the other steps. sqlite3_reset does not clear any column bindings. Thanks for the explanation. It makes sense. Thanks Gaurav -- Sent from: http://sqlite.1065341.n5.nabble.com/ _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users ___________________________________________ Gunter Hick Software Engineer Scientific Games International GmbH FN 157284 a, HG Wien Klitschgasse 2-4, A-1130 Vienna, Austria Tel: +43 1 80100 0 E-Mail: h...@scigames.at This communication (including any attachments) is intended for the use of the intended recipient(s) only and may contain information that is confidential, privileged or legally protected. Any unauthorized use or dissemination of this communication is strictly prohibited. If you have received this communication in error, please immediately notify the sender by return e-mail message and delete all copies of the original communication. Thank you for your cooperation. _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
