create table emp(id number(2) constraint pk_id primary key,
name varchar2(20) unique,
sex varchar2(10) constraint ch_sex check(sex='男'or sex='女'),
job varchar2(20) ,
joindate date,
salary number(10,2),
dept number(4));
insert into emp(value1,value2,....) values(value1,value2....);
select * from emp where salary>500 or job='manger'and name like 'J%';
select dept ,count(* ) from emp group by dept;
同意楼上