带in关头字的调集查询
方式/步骤
- 1
只查询ID为2,4,6的信息
select username from user where id in (2,4,6);

- 2
除了不查询ID为2,4,6的信息外,其他的信息
select username from user where not id in (2,4,6);

- 3
查询sex中开首为w的信息
select username,age from user where sex like 'w%';

- 4
查询address中中心有u的信息,'_'的利用
select username,age from user where address like '_u%';
查询address中含有a的信息
select username,age from user where address like '%a%';


- 5
按春秋排序
select*from user order by age asc;(升序)
select*from user order by age desc;(j降序)


- 6
limit的利用
限制查询前5个信息








