MySQL数据库数据类型之集合类型SET测试总结(3)

发表于:2013-12-14来源:IT博客大学习作者:Eugene点击数: 标签:MySQL
+----+-------------+-----------+ | ID | Work_Option | Work_City | +----+-------------+-----------+ | 3 | | hangzhou | +----+-------------+-----------+ 1 row in set (0.00 sec) root@localhost : test 03:

  +----+-------------+-----------+

  | ID | Work_Option | Work_City |

  +----+-------------+-----------+

  | 3 | | hangzhou |

  +----+-------------+-----------+

  1 row in set (0.00 sec)

  root@localhost : test 03:10:30> SELECT * FROM mysqlops_set WHERE Work_City=7;

  +----+-------------+---------------------------+

  | ID | Work_Option | Work_City |

  +----+-------------+---------------------------+

  | 8 | DBA,SA,NA | shanghai,beijing,hangzhou |

  +----+-------------+---------------------------+

  1 row in set (0.00 sec)

  root@localhost : test 03:13:13> SELECT * FROM mysqlops_set WHERE Work_City=63;

  +----+-------------+----------------------------------------------------+

  | ID | Work_Option | Work_City |

  +----+-------------+----------------------------------------------------+

  | 9 | DBA,SA,NA | shanghai,beijing,hangzhou,shenzhen,guangzhou,other |

  +----+-------------+----------------------------------------------------+

  1 row in set (0.00 sec)

  集合类型SET元素的存储顺序梳理:

  l 集合类型字段定义的值域列表信息

集合类型值域列表顺序

值域列表顺序对应的元素值

存储序号二进制编码

二进制编码对应的十进制值

1

shanghai

0000,0001

1

2

beijing

0000,0010

2

3

hangzhou

0000,0100

4

4

shenzhen

0000,1000

8

5

guangzhou

0001,0000

16

6

other

0010,0000

32

  l 集合类型字段存储的值

自增序列字段的值

集合类型字段Work_City的值

二进制编码

十进制值

1

shanghai

0000,0001

1

2

空格字符串

0000,0000

0

3

hangzhou

0000,0100

4

4

空格字符串

0000,0000

0

5

shanghai

0000,0001

1

6

shanghai

0000,0001

1

7

Shanghai,beijing

0000,0011

3

8

shanghai,beijing,hangzhou

0000,0111

7

9

shanghai,beijing,hangzhou,shenzhen,guangzhou,other

0011,1111

63

10

空格字符串

0000,0000

0

11

shanghai

0000,0001

1

12

shanghai

0000,0001

1

13

hangzhou

0000,0100

4

20

shanghai,beijing

0000,0011

3

原文转自:http://blogread.cn/it/article/5114