關於PHPMYADMIN的MYSQL - 創建表關係

Question

我想與MYSQL PHPMYADMIN創建表關係。 但沒有約束。

這裏是我做的：

CREATE TABLE runs (
code_teachers int(8), 
code_department int(8), 
primary key(code_teachers, code_department), 
foreign key(code_teachers)references teachers, 
foreign key(code_department)references department 
); 

因此，大家可以看到我試圖創建一個從教師code_teachers之間運行的命名錶對應關係從部門create table和code_department創建表。

但是對於某些未知的原因，當我進入desinger時，它並沒有使關係。 因此，如果有人知道我的問題的答案，歡迎告訴我因爲ima在這裏瘋狂。

Answer 1

你嘗試

FOREIGN KEY (columnName) REFERENCES tableName(columnName) 

表名似乎是從您的查詢失蹤。 外鍵需要引用其他表中的列。

Wikipedia說：

• In the context of relational databases, a foreign key is a referential constraint between two tables. A foreign key is a field in a relational table that matches a candidate key of another table. The foreign key can be used to cross-reference tables.

mySQL.com說：

• Foreign key relationships involve a parent table that holds the central data values, and a child table with identical values pointing back to its parent. The FOREIGN KEY clause is specified in the child table.