SQL Server 2012 多表銜接查詢功用實例代碼

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廢話不多說了，直接給大家貼代碼了，詳細代碼如下所示：

-- 穿插銜接發生笛卡爾值 (X*Y)
SELECT *
FROM  Student
    cross Join dbo.ClassInfo 
--另外一種寫法
SELECT *
FROM  Student , ClassInfo 
-- 內銜接 (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，而且能夠是針對某個表的
SELECT *
FROM  Student
    INNER JOIN dbo.ClassInfo ON dbo.Student.Class = dbo.ClassInfo.ID
    AND dbo.Student.Class IN (1,2) -- 針對Student表添加查詢條件
-- 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;
--自銜接 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;
-- 全外銜接
SELECT *
FROM  Student
    FULL OUTER JOIN dbo.ClassInfo ON dbo.Student.Class = dbo.ClassInfo.ID;
-- 外銜接和內銜接的區別是：
-- 內銜接，on條件不契合的話，會過濾掉數據
-- 外銜接，以保存表為主，on條件成立顯示數據，否則顯示NULL
--Union 縱向銜接
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 去反復
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,掃除
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

以上所述是給大家引見的SQL Server 2012 多表銜接查詢功用實例代碼，希望對大家有所協助，假如大家有任何疑問歡送給我留言，會及時回復大家的！