Oarcle 入门之where关键字
--where 关键字
--作用:过滤行 *将需要的行用where引导出来
用法:
1.判断符号:=,!=,<>,<,>,<=,>=,any,some,all;
例如:要求在表中sal等于1000 select * from emp where sal=1000;
求sal大于1500且大于1800大于2000 select * from emp where sal !=any(1500,1800,2000);
* some和any 用法一致,all表示为全部;
2. is null,is not null
例如:select * from empty where comm is not null;
3.between x and Y
例如查询工人薪水在2000~3000之间的员工信息 select * from emp where sal between 2000 and 3000;
4.and ,or , not
例如: select * from emp where sal >=2000 and sal<=3000;
5.int (list),not in(list)
查询职务为MANAGER和ANALYST的员工信息 select * from where job in ('MANAGER','ANALYST');
查询工资不为3000和5000的员工信息 select * from emp where sal not in (3000,5000);