Assuming the "id" is the primary key of your table "table_name", your statement will list the id of all the records present (full scan, reading every entry of the implicit primary key index).
To find out if a specific record exists, use "select count() from table_name where id = <key value>" to return a single row with the number of records found. This may be faster only if id has a primary key or unique constraint or is the first field of a declared index. -----Urspr?ngliche Nachricht----- Von: sqlite-users-bounces at mailinglists.sqlite.org [mailto:sqlite-users-bounces at mailinglists.sqlite.org] Im Auftrag von Jim Wang Gesendet: Donnerstag, 10. M?rz 2016 09:01 An: sqlite-users at mailinglists.sqlite.org Betreff: [sqlite] jude a record is exist or not hi,all As usual, we judge a record is exist or not in a data base is :select id from table_name. Except the above method, Is there any method which could judge a record is exist or not much faster than the above method. I am looking forward to hearing from you. Jim Wang. _______________________________________________ sqlite-users mailing list sqlite-users at 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: hick at 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.
