I have two SQL tables: Users and clients. Every row in the users table has a set of clients in the clients table, linked by the users table id field and the clients table user_id field. The users ...
I have a few column with UNIQUE INDEX. In some queries, duplicates should be acceptable, in which a postfix should be added to the value. For example, if test title exits, we change it to test ...
I am hashing keys from one table that provides a 256 bit (64 char length) alphanumeric string that I intend to use in a second table as a foreign key. The engine of choice here is InnoDB. There are ...
Consider a table of CREATE TABLE test ( id int(11) unsigned NOT NULL AUTO_INCREMENT, external_id int(11), number smallint(5), value varchar(255), UNIQUE INDEX (external_id, number), PRIMARY KEY(id) ...
Is there any different how mysql treats UNIQUE (column1, column2), INDEX (column1) and UNIQUE INDEX (column1, column2) and UNIQUE (column1, column2) In the latter, I think mysql will ...