MySQLではデータベースの一貫性を保つため、 外部キー （Foreign Key） 制約がサポートされています。外部キーとは、 2つのテーブル （親テーブルと子テーブル） 間における参照整合性を保つために設定される制約です。InnoDBとNDBストレージエンジンのみで ...

Os itens entre `[]` são opcionais. Assim se você omitir o nome da restrição de chave estrangeira ou o nome da chave estrangeira o MySQL irá gerar um nome automaticamente. O MySQL tem cinco opções de ...

ON UPDATE CASCADE :- When we create a foreign key using UPDATE CASCADE the referencing rows are updated in the child table when the referenced row is updated in the parent table which has a primary ...

I'm working on a web app, and it part of it, there is a very simple database-driven file/document manager. As a file manager, there is the possibility of sub-folders. So in the DB, I have the ...

We are rewriting a large Django application which uses a MySQL database, and the database schema needs to undergo major modifications. We're also porting the app to use PostgreSQL, for a couple of ...

Today, Structured Query Language is the standard means of manipulating and querying data in relational databases, though with proprietary extensions among the products. The ease and ubiquity of SQL ...