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 ...

Note that the "P_Id" column in the "Orders" table points to the "P_Id" column in the "Persons" table. In MySQL, the FOREIGN KEY on one table is used to point a PRIMARY KEY in another table. We have ...

A FOREIGN KEY is a field (or collection of fields) in one table, that refers to the PRIMARY KEY in another table. The table with the foreign key is called the child table, and the table with the ...

Note that the "P_Id" column in the "Orders" table points to the "P_Id" column in the "Persons" table. In MySQL, the FOREIGN KEY on one table is used to point a PRIMARY KEY in another table. We have ...

Following more than 12 months of development and preview releases, Oracle has announced general availability of MySQL Cluster 7.3, bringing a number of important new features and enhancements to the ...

Oracle announced the general availability of MySQL Cluster 7.3, which adds foreign key support, a new NoSQL JavaScript Connector for node.js, and an auto-installer to make setting up clusters easier.

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 ...

I encountered this issues with a migration rollback failing to remove a unique index (in my case, composed) if one of the columns used in it are also used in a foreign key constraint and, hence, in a ...