找忘记填写性别的员工

已知：

Table:   （员工 emp1）
id   name
1 a
2 b
3 c
4  d
 
Table:( 性别 sext)
 
id sex
1 男
4 女
5 男
 
找出忘记填写性别的员工（用Oracle的两种方式）

Create Table Empl(  Id Number(4) primary key,  name varchar2(10));Insert Into Empl Values (1,'a') ;Insert Into Empl Values (2,'b') ;Insert Into Empl Values (3,'c') ;Insert Into Empl Values (4,'d') ;Insert Into Empl Values (5,'e') ;Select * From Empl;/*-----------------------------------------------*/Create Table sext(  Id Number(4) Primary Key,  sex varchar2(10));Insert Into Sext Values(1,'男');Insert Into Sext Values(3,'女');Insert Into Sext Values(5,'男');Select * From Sext;/*----- 找出忘记填写性别的员工（用Oracle的两种方式） -------------*/Select Id,Name From Empl E Where E.Id Not In(Select Id From Sext); --minus差集Select Id From Empl Minus Select Id From Sext; -- <>Select * From Empl Where Id <> All(Select Id From Sext); -- 先求id的差集Select E.* From Empl E,(Select Id From Empl Minus Select Id From Sext) S /*临时表s*/Where E.Id = S.Id; --左外莲接1Select E.Id,E.Name From Empl E,Sext S Where E.Id=S.Id(+) And S.Sex Is Null; --左外莲接2Select * From EmplLeft Outer Join Sext On Empl.Id = Sext.Id Where Sext.Sex Is Null; --not existsSelect * From Empl E Where Not Exists    (Select * From Sext S      Where E.Id = S.Id); --not inSelect * From Empl Where Id Not In     (Select Empl.Id     From Empl, Sext     Where Empl.Id = Sext.Id);--Intersect相交Select Name From Empl Where Id Not In     (Select Id From Empl     Intersect     Select Id From Sext);--此种先求两个表id的合集。当count(*)=2表示id重复，<2时表示未填写Select * From Empl E Where (Select Count(*) From     (Select Id From Empl Union All Select Id From Sext) TWhere T.Id=E.Id)<2;