MySQL

Doctrine cannot add or update child row error

Doctrine worked mostly with InnoDB tables. And when you create foreign keys you must set onUpdate and onDelete events to “CASCADE” or “NO ACTION”, cause if you set them to NULL(the same if you don’t set them) they automatically set in “RESTRICT”. This may cause some problems.

The second mistake(that i did many times) it’s forgetting to rename FOREIGN KEY when rename tables or dependent cols. So don’t forget about names)

Реализация релевантности в MySQL InnoDB

Нашел седня интересный выход на тему релевантности в таблицах не MyISAM в MySQL.
Запрос реализует выборку количества вхождений подстроки в строку.