表的插入、更新、删除、合并操作_15_ 按照默认值更新表

                                     按照默认值更新表

需求描述

需求:更新deptno对应是50的dept表的loc字段成默认值.

解决方法:这里通过UPDATE TableName SET ColName=DEFAULT …的方式来更新数据.

注: 数据库数据集SQL脚本详见如下链接地址

​​员工表结构和数据初始化SQL脚本​​

SQL代码

-- SQL Server:
BEGIN TRAN
SELECT * FROM dept WHERE deptno = 50;

UPDATE dept
SET loc = DEFAULT
WHERE deptno = 50;

SELECT * FROM dept WHERE deptno = 50;
ROLLBACK TRAN

-- MySQL:
BEGIN;
SELECT * FROM dept WHERE deptno=40;

UPDATE dept
SET loc= default
WHERE deptno = 40;
SELECT * FROM dept WHERE deptno=40;
ROLLBACK;

-- Oracle:
SELECT * FROM dept WHERE deptno=40;

UPDATE dept
SET loc= default
WHERE deptno=40;

SELECT * FROM dept WHERE deptno=40;
ROLLBACK;

执行结果