下面我建兩個表,並執行一系列sql語句,仔細觀察sql執行后表中數據的變化,很容易就能理解多表聯合更新的用法
student表 class表

1. 執行 UPDATE student s , class c SET s.class_name='test00',c.stu_name='test00' WHERE s.class_id = c.id
student表 class表

2. 執行 UPDATE student s JOIN class c ON s.class_id = c.id SET s.class_name='test11',c.stu_name='test11'
student表 class表

3. 執行 UPDATE student s LEFT JOIN class c ON s.class_id = c.id SET s.class_name='test22',c.stu_name='test22'
student表 class表

4. 執行 UPDATE student s RIGHT JOIN class c ON s.class_id = c.id SET s.class_name='test33',c.stu_name='test33'
student表 class表

5. 執行 UPDATE student s JOIN class c ON s.class_id = c.id SET s.class_name=c.name , c.stu_name=s.name
student表 class表

原文地址:https://blog.csdn.net/u012604745/article/details/80642015
