On Fri, 3 Aug 2018 15:11:06 +0200, Csányi Pál <csanyi...@gmail.com> wrote:
>The database is so far with only one table: >CREATE TABLE MyLengthOfService ( > id INT PRIMARY KEY > UNIQUE, > WorkPlaceName TEXT, You shouldn't use UNIQUE for the PRIMARY KEY. Any PRIMARY KEY is implicitly unique by itself. Adding the UNIQUE keyword might create an extra, redundant, index, which will eat file space and processing time without having any added value. And it may confuse the query optimizer. The idea is that any set (table) may have more than one key to uniquely identify a tuple (row). Each key is called a candidate key. Only one of those keys can be choosen to be the PRIMARY KEY. All other candidate keys can get honored by adding the UNIQUE clause, to recognize them as alternative keys. -- Regards, Kees Nuyt _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
