sql server Right Outer Join用法

Right Outer Join 運算子返回滿足第二個（底端）輸入與第一個（頂端）輸入的每個匹配行的聯結的每行。此外，它還返回第二個輸入中在第一個輸入中沒有匹配行的任何行，即與 NULL 聯結。如果 Argument 列內不存在任何聯結謂詞，則每行都是一個匹配行。

一、聯結（ join）

通過聯結，可以根據各個表之間的邏輯關係從兩個或多個表中檢索資料。聯結表示應如何使用一個表中的資料來選擇另一個表中的行。

聯結條件通過以下方法定義兩個表在查詢中的關聯方式：

指定每個表中要用於聯結的列。典型的聯結條件在一個表中指定外鍵，在另一個表中指定與其關聯的鍵。指定比較各列的值時要使用的邏輯運算子（=、<> 等）。

下面的 SQL 陳述式說明 titles 表和 publishers 表之間的左向外聯結包括所有的書名，甚至包括那些沒有出版商資訊的書名： Use pubs    SELECT titles.title_id,    titles.title, publishers.pub_name    FROM titles LEFT OUTER JOIN publishers ON titles.pub_id = publishers.pub_id

執行個體

1> create table employee(
2>     ID          int,
3>     name        nvarchar (10),
4>     salary      int )
5> GO
1>
2> create table job(
3>     ID              int,
4>     title nvarchar  (10),
5>     averageSalary   int)
6> GO
1>
2>
3> insert into employee (ID, name, salary) values (1,  'Jason', 1234)
4> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (2,  'Robert', 4321)
2> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (3,  'Celia', 5432)
2> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (4,  'Linda', 3456)
2> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (5,  'David', 7654)
2> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (6,  'James', 4567)
2> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (7,  'Alison', 8744)
2> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (8,  'Chris', 9875)
2> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (9,  'Mary', 2345)
2> GO

(1 rows affected)
1>
2> insert into job(ID, title, averageSalary) values(1,'Developer',3000)
3> GO

(1 rows affected)
1> insert into job(ID, title, averageSalary) values(2,'Tester', 4000)
2> GO

(1 rows affected)
1> insert into job(ID, title, averageSalary) values(3,'Designer', 5000)
2> GO

(1 rows affected)
1> insert into job(ID, title, averageSalary) values(4,'Programmer', 6000)
2> GO

(1 rows affected)
1>
2>
3>
4> select * from employee;
5> GO
ID          name       salary
----------- ---------- -----------
          1 Jason             1234
          2 Robert            4321
          3 Celia             5432
          4 Linda             3456
          5 David             7654
          6 James             4567
          7 Alison            8744
          8 Chris             9875
          9 Mary              2345

(9 rows affected)
1> select * from job;
2> GO
ID          title      averageSalary
----------- ---------- -------------
          1 Developer           3000
          2 Tester              4000
          3 Designer            5000
          4 Programmer          6000

(4 rows affected)
1>
2> -- RIGHT OUTER JOIN includes all the information from the table on the right.
3>
4> SELECT e.id, e.name, j.title
5> FROM Employee e
6> RIGHT OUTER JOIN job j
7>              ON e.id = j.id
8> GO
id          name       title
----------- ---------- ----------
          1 Jason      Developer
          2 Robert     Tester
          3 Celia      Designer
          4 Linda      Programmer

(4 rows affected)
1>
2>
3> drop table employee;
4> drop table job;
5> GO
1>
2>

執行個體二 RIGHT OUTER JOIN

外串連（Outer join）文法

左外串連的文法為： SELECT 列 FROM 表1   LEFT   [OUTER]JOIN 表2 ON 表1.列1=表2.列2

右外串連的文法為： SELECT select_list FROM  表1 RIGHT[OUTER]JOIN 表2 ON 表1.列1=表2.列2

全外串連(完整外部聯結)的文法為： SELECT select_list FROM  表1 FULL[OUTER]  JOIN  表2 ON 表1.列1=表2.列2

執行個體

1> create table employee(
2>     ID          int,
3>     name        nvarchar (10),
4>     salary      int )
5> GO
1>
2> create table job(
3>     ID              int,
4>     title nvarchar  (10),
5>     averageSalary   int)
6> GO
1>
2>
3> insert into employee (ID, name, salary) values (1,  'Jason', 1234)
4> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (2,  'Robert', 4321)
2> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (3,  'Celia', 5432)
2> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (4,  'Linda', 3456)
2> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (5,  'David', 7654)
2> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (6,  'James', 4567)
2> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (7,  'Alison', 8744)
2> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (8,  'Chris', 9875)
2> GO

(1 rows affected)
1> insert into employee (ID, name, salary) values (9,  'Mary', 2345)
2> GO

(1 rows affected)
1>
2> insert into job(ID, title, averageSalary) values(1,'Developer',3000)
3> GO

(1 rows affected)
1> insert into job(ID, title, averageSalary) values(2,'Tester', 4000)
2> GO

(1 rows affected)
1> insert into job(ID, title, averageSalary) values(3,'Designer', 5000)
2> GO

(1 rows affected)
1> insert into job(ID, title, averageSalary) values(4,'Programmer', 6000)
2> GO

(1 rows affected)
1>
2>
3> select * from employee;
4> GO
ID          name       salary
----------- ---------- -----------
          1 Jason             1234
          2 Robert            4321
          3 Celia             5432
          4 Linda             3456
          5 David             7654
          6 James             4567
          7 Alison            8744
          8 Chris             9875
          9 Mary              2345

(9 rows affected)
1> select * from job;
2> GO
ID          title      averageSalary www.111cn.net/6700s/
----------- ---------- -------------
          1 Developer           3000
          2 Tester              4000
          3 Designer            5000
          4 Programmer          6000

(4 rows affected)
1>
2>
3> SELECT e.name FROM Employee e
4> RIGHT OUTER JOIN job j
5>               ON e.id = j.id
6> WHERE e.id IS NOT NULL
7> GO
name
----------
Jason
Robert
Celia
Linda

(4 rows affected)
1>
2>
3> drop table employee;
4> drop table job;
5> GO
1>