mysql中字符串和整型自动转换的问题

Mon, 14 Dec 2020 18:47:29 +0800

表结构如下

desc info;
+-------+-----------------+------+-----+---------+----------------+
| Field | Type            | Null | Key | Default | Extra          |
+-------+-----------------+------+-----+---------+----------------+
| id    | int(8) unsigned | NO   | PRI | NULL    | auto_increment |
| name  | varchar(20)     | YES  |     | NULL    |                |
+-------+-----------------+------+-----+---------+----------------+
2 rows in set (0.00 sec)

执行sql.

insert into info values ('', 'xxx');
insert into info values ('', 'yyy');

查询记录.

select * from info;
+----+------+
| id | name |
+----+------+
|  1 | xxx  |
|  2 | yyy  |
+----+------+
2 rows in set (0.00 sec)

执行下面sql.

select * from info where id = 1;

select * from info where id = '1aaaa';

你先想想结果会是什么。

一次惊心动魄的Mysql更新操作

Tue, 19 May 2020 17:16:53 +0800

问题描述

# 表结构
MySQL > desc user_packages;
+----------------+---------------------+------+-----+---------------------+----------------+
| Field          | Type                | Null | Key | Default             | Extra          |
+----------------+---------------------+------+-----+---------------------+----------------+
| up_id          | bigint(20) unsigned | NO   | PRI | NULL                | auto_increment |
| start_date     | date                | NO   |     | NULL                |                |
| end_date       | date                | NO   |     | NULL                |                |
| up_created     | datetime            | NO   | MUL | 0000-00-00 00:00:00 |                |
| up_updated     | datetime            | NO   |     | 0000-00-00 00:00:00 |                |
+----------------+---------------------+------+-----+---------------------+----------------+
5 rows in set (0.00 sec)

MySQL > select * from user_packages limit 5;
+-------+------------+------------+
| up_id | start_date | end_date   |
+-------+------------+------------+
|   185 | 2018-04-01 | 2018-06-30 |
|   186 | 2018-04-01 | 2018-06-30 |
|   187 | 2018-04-01 | 2018-06-30 |
|   188 | 2018-04-01 | 2018-06-30 |
|   189 | 2018-04-01 | 2018-06-30 |
+-------+------------+------------+
5 rows in set (0.00 sec)

操作过程

需要更新某条记录的end_date字段，执行sql如下：

Mysql on 流动

mysql中字符串和整型自动转换的问题

一次惊心动魄的Mysql更新操作

问题描述

操作过程