廢話不多說了，直接給大家貼代碼了，具體代碼如下所示：
-- 交叉連接產生笛卡爾值 (X*Y)
SELECT *
FROM Student
cross Join dbo.ClassInfo
--另外一種寫法
SELECT *
FROM Student , ClassInfo
-- 內連接 (Inner 可以省略)
SELECT *
FROM Student
JOIN dbo.ClassInfo ON dbo.Student.Class = dbo.ClassInfo.ID;
-- Inner Join
SELECT *
FROM Student
INNER JOIN dbo.ClassInfo ON dbo.Student.Class = dbo.ClassInfo.ID;
-- on 條件，通常是 主外鍵，但是不限於主外鍵
-- on 條件，允許有多個，而且可能是針對某個表的
SELECT *
FROM Student
INNER JOIN dbo.ClassInfo ON dbo.Student.Class = dbo.ClassInfo.ID
AND dbo.Student.Class IN (1,2) -- 針對Student表增加查詢條件
-- 不等於 (笛卡爾值減去 相等的值)
SELECT *
FROM Student
INNER JOIN dbo.ClassInfo ON dbo.Student.Class <> dbo.ClassInfo.ID;
--自連接 從Class表中查詢到Class所在的系
SELECT T1.* ,T2.ClassName FROM dbo.ClassInfo AS T1
INNER JOIN dbo.ClassInfo AS T2 ON T1.PID=T2.ID
-- Left Join
SELECT *
FROM Student
Left JOIN dbo.ClassInfo ON dbo.Student.Class = dbo.ClassInfo.ID;
-- Right Join
SELECT *
FROM Student
RIGHT JOIN dbo.ClassInfo ON dbo.Student.Class = dbo.ClassInfo.ID;
-- 全外連接
SELECT *
FROM Student
FULL OUTER JOIN dbo.ClassInfo ON dbo.Student.Class = dbo.ClassInfo.ID;
-- 外連接和內連接的區別是：
-- 內連接，on條件不符合的話，會過濾掉數據
-- 外連接，以保留表為主，on條件成立顯示數據，否則顯示NULL
--Union 縱向連接
SELECT StuID,StuName,StuEnName,StuAge,StuBirthday
FROM Student WHERE StuID<=2
UNION
SELECT StuID,StuName,StuEnName,StuAge,StuBirthday
FROM dbo.Student WHERE StuID>2
--Union 去重復
SELECT StuSex
FROM Student WHERE StuID<=2
UNION
SELECT StuSex
FROM dbo.Student WHERE StuID>2
--Union 顯示全部
SELECT StuSex
FROM Student WHERE StuID<=2
UNION ALL
SELECT StuSex
FROM dbo.Student WHERE StuID>2
--Except 差集,排除
SELECT StuID,StuName,StuEnName,StuAge,StuBirthday
FROM Student
Except
SELECT StuID,StuName,StuEnName,StuAge,StuBirthday
FROM dbo.Student WHERE StuID<=2
--Intersect 交集
SELECT StuID,StuName,StuEnName,StuAge,StuBirthday
FROM Student WHERE StuID>=2
Except
SELECT StuID,StuName,StuEnName,StuAge,StuBirthday
FROM dbo.Student WHERE StuID<=3
以上所述是小編給大家介紹的SQL Server 2012 多表連接查詢功能實例代碼，希望對大家有所幫助，如果大家有任何疑問歡迎給我留言，小編會及時回復大家的！
