条件where

语法：

select column1, column2 from table_name where [condition]

可以使用比较或逻辑运算符指定条件：

and:    select * from company where age >= 25 and salary >= 65000;

not null:  select * from company where age is not null;

like:    select * from company where name like '%ki';

in:  select * from company where age in ( 25, 27 );

between:  select * from company where age between 25 and 27;