bit类型

Posted 2020-11-19 bibiafa

表结构

 Table: t3
Create Table: CREATE TABLE `t3` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `bi` bit(8) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

 

insert into t3 (bi) values (11); 

 对于bit类型，实际插入的是二进制数 1011

 

select bi+0 from t3;

执行结果

+------+
| bi+0 |
+------+
|   11 |
+------+

对于bit类型，查询数据的格式是 (字段+0)

  

select bin(bi+0),oct(bi+0),hex(bi+0) from t3;

执行结果

+-----------+-----------+-----------+
| bin(bi+0) | oct(bi+0) | hex(bi+0) |
+-----------+-----------+-----------+
| 1011      | 13        | B         |
+-----------+-----------+-----------+

 

在insert时插入二进制数据的语法是 b‘value‘

insert into t3 (bi) values (b‘11‘)

 

select bi+0, bin(bi+0),oct(bi+0),hex(bi+0) from t3;

执行结果

+------+-----------+-----------+-----------+
| bi+0 | bin(bi+0) | oct(bi+0) | hex(bi+0) |
+------+-----------+-----------+-----------+
|   11 | 1011      | 13        | B         |
|    3 | 11        | 3         | 3         |
+------+-----------+-----------+-----------+