Question

我有一张人员表。人们擅长某种语言并给予他们体重。我的表格如下：

Person

ID  Name    Description
1   Rodra   Some..
2   Rakib   Some..
3   Samsad  Some..
4   Foysal  Some..

Language
TypeID  TypeName
1   C#  
2   Asp.Net
3   Python
4   JSP
5   Java
6   Jquery
7   Android

PersonSkill

ID  PersonID    TypeID  Weight
1   1           1       60
2   1           3       50
3   1           7       40
4   2           1       80
5   2           2       70
6   3           1       90
7   3           2       50
8   4           1       60
9   4           2       50
10  4           6       40
11  4           7       55

现在我想查询那些知道c＃（TypeId 1）＆gt; 65和Asp.net（TypeID 2）＆gt; 65的人。怎么做？任何人都非常感谢。

Answer 1

Select * 
FROM person
WHERE EXISTS(SELECT * FROM PersonSkill WHERE PersonId = Person.Id AND TypeID = 1 AND Weight>65)
AND EXISTS(SELECT * FROM PersonSkill WHERE PersonId = Person.Id AND TypeID = 2 AND Weight>65)

Answer 2

select p.* from 
person p 
JOIN personSkill ps ON p.ID=ps.PersonID 
JOIN Language l ON l.TypeID=ps.TypeID 
WHERE (l.TypeName = 'c#' AND ps.weight>65) 
AND 
(l.TypeName = 'Asp.net' AND ps.weight>65)

行法就像列数据库查询一样

2 个答案: