外鍵是在一個表中的一組一個或多個列的引用在另一個表中的主鍵。沒有你需要

外鍵是在一個表中的一組一個或多個列的引用在另一個表中的主鍵。沒有你需要的地方，正式“指定”的一個外鍵的任何特殊代碼，配置或表定義。

結果 (英文) 1:

Is a foreign key in the table references a set of one or more primary key in another table column. There is no place you need any special code formally "designated" a foreign key, configuration, or the table definition.

結果 (英文) 2:

A foreign key is the primary key in one table where a reference to a set of one or more columns is in another table. There is no special code, configuration, or table definition for a foreign key that you need to formally "designate" a foreign key.

結果 (英文) 3:

A foreign key is a primary key in another table that refers to a group of one or more columns in one table. There is no place you need to formally "specify" any special code, configuration or table definition for a foreign key.