SQL43 将所有to_date为9999-01-01的全部更新为NULL

本文最后更新于：2022年4月9日 中午


题目描述

将所有to_date为9999-01-01的全部更新为NULL,且 from_date更新为2001-01-01。

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CREATE TABLE IF NOT EXISTS titles_test (
id int(11) not null primary key,
emp_no int(11) NOT NULL,
title varchar(50) NOT NULL,
from_date date NOT NULL,
to_date date DEFAULT NULL);

insert into titles_test values ('1', '10001', 'Senior Engineer', '1986-06-26', '9999-01-01'),
('2', '10002', 'Staff', '1996-08-03', '9999-01-01'),
('3', '10003', 'Senior Engineer', '1995-12-03', '9999-01-01'),
('4', '10004', 'Senior Engineer', '1995-12-03', '9999-01-01'),
('5', '10001', 'Senior Engineer', '1986-06-26', '9999-01-01'),
('6', '10002', 'Staff', '1996-08-03', '9999-01-01'),
('7', '10003', 'Senior Engineer', '1995-12-03', '9999-01-01');

更新后的值:

titles_test 表的值：

id emp_no title from_date to_date
1 10001 Senior Engineer 2001-01-01 NULL
2 10002 Staff 2001-01-01 NULL
3 10003 Senior Engineer 2001-01-01 NULL
4 10004 Senior Engineer 2001-01-01 NULL
5 10001 Senior Engineer 2001-01-01 NULL
6 10002 Staff 2001-01-01 NULL
7 10003 Senior Engineer 2001-01-01 NULL

输入描述

无

输出描述

无

题解

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update titles_test set from_date='2001-01-01',to_date=NULL where to_date='9999-01-01';