Mysql sets boolean type operations

Mysql sets boolean type

1. Tinyint type

We create a test table and set its bl field to boolean type

create table test(
	id int PRIMARY key,
	status boolean
)

This will create success. If you look at the statement after creating the table, you will find that MySQL replaces it with tinyint(1).

Tinyint can only store integers from 0 to 255. Since there is no boolean type in MySQL, the tinyint[1] type is used to represent it. In MySQL, boolean=tinyint[1]

0 represents false

1 represents true

Simply define the attribute as a Boolean value in pojo: private Boolean status

When the type is tinyint[1], no matter whether it stores 0, 1, 2, 3, 4, etc., the returned value is of boolean type. When we need to use it to store integer values, we can set it to tinyint[4]

MySQL boolean type solution

1. Source of demand

Today, when defining a requirement, when using REST request to operate the database, the value corresponding to a certain key must be a boolean value.

In MySQL, a field must be a Boolean value.

{
	"neId": 2,
	"data": [{
			"alarmLevel": "1",
			"selection": true
		},
		{
			"alarmLevel": "2",
			"selection": true
		}
	]
}

2. Plundering the people’s blood and sweat

When setting boolean in MySQL, I found that there was no such type. Later, I searched "民脂民贵" and found the solution:

The boolean type is represented by tinyint.

3. Create a database

Standard construction structure:

DROP TABLE IF EXISTS db_msp.alarm_shield_level;
CREATE TABLE db_msp.`alarm_shield_level` (
  `neId` int(11) NOT NULL,
  `alarmLevel` varchar(32) NOT NULL,
  `alarmLevelCh` varchar(32) NOT NULL,
  `alarmLevelEn` varchar(32) NOT NULL,
  `enableStatus` tinyint(1) NOT NULL,
  PRIMARY KEY (`neId`,`alarmLevel`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8 ;

4. Conclusion

When MySQL saves Boolean values, 1 is used to represent TRUE and 0 is used to represent FALSE. The Boolean type in MySQL is tinyint(1).

When checking the library in the Java code, if the data in the library is 1, the code returns true; if the data in the library is 0, the code returns false.

The above is my personal experience. I hope it can give you a reference. I also hope that you will support 123WORDPRESS.COM.