python学习笔记(71) SQL语句数据行操作补充

增

　　insert into tb1(name,age) values('alex',12),('egg',18);

　　insert into tb2(name,age) select name,age from tb1;

删

　　delete from tb1 where id>2 and name='alex'

改

　　update tb2 set name='alex',age=19 where id>12 and name='xx'

查

　　select * from tb1;

　　select id,name from tb1;

　　select id,name from tb1 where id>12 or name='alex';

　　select id,name as cname from tb1 where id>12 or name='alex';

　　select name,age,11 from tb2　　# 11是常量

　　select * from tb1 where id in (1,2,3);

　　select * from tb1 where id not in (1,2,3);

　　select * from tb1 where id between 1 and 5;　　# 闭区间

　　select * from tb1 where id in (select nid from 表);　　# 先执行括号语句

通配符：

　　select * from tb1 where name like "a%";　　# 后续任意字符

　　select * from tb1 where name like "a_";　　# 后续一个字符

分页：

　　select * from tb1 limit 10;　　# 前10项

　　select * from tb1 limit 0,10;　　#从0项开始前10项

　　select * from tb1 limit 10,10;

　　select * from tb1 limit 10 offset 20;　　# 从20开始前10项

排序：

　　select * from tb1 order by id asc;

　　select * from tb1 order by id desc;

　　取后10条数据

　　select * from tb1 order by id desc limit 10;