Using Derived Tables : Inline view « View « SQL Server / T-SQL






Using Derived Tables

 


Derived tables are SELECT statements that act as tables in the FROM clause.
Derived tables can sometimes provide better performance than using temporary tables.

9>
10> CREATE TABLE employee(
11>    id          INTEGER NOT NULL PRIMARY KEY,
12>    first_name  VARCHAR(10),
13>    last_name   VARCHAR(10),
14>    salary      DECIMAL(10,2),
15>    start_Date  DATETIME,
16>    region      VARCHAR(10),
17>    city        VARCHAR(20)
18> );
19> GO
1> INSERT INTO employee VALUES (1, 'Jason' ,  'Martin', 5890,'2005-03-22','North','Vancouver');
2> INSERT INTO employee VALUES (2, 'Alison',  'Mathews',4789,'2003-07-21','South','Utown');
3> INSERT INTO employee VALUES (3, 'James' ,  'Smith',  6678,'2001-12-01','North','Paris');
4> INSERT INTO employee VALUES (4, 'Celia' ,  'Rice',   5567,'2006-03-03','South','London');
5> INSERT INTO employee VALUES (5, 'Robert',  'Black',  4467,'2004-07-02','East','Newton');
6> INSERT INTO employee VALUES (6, 'Linda' ,  'Green' , 6456,'2002-05-19','East','Calgary');
7> INSERT INTO employee VALUES (7, 'David' ,  'Larry',  5345,'2008-03-18','West','New York');
8> INSERT INTO employee VALUES (8, 'James' ,  'Cat',    4234,'2007-07-17','West','Regina');
9> INSERT INTO employee VALUES (9, 'Joan'  ,  'Act',    6123,'2001-04-16','North','Toronto');
10> GO

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)
1> select * from employee;
2> GO
id          first_name last_name  salary       start_Date              region     city
----------- ---------- ---------- ------------ ----------------------- ---------- --------------------
          1 Jason      Martin          5890.00 2005-03-22 00:00:00.000 North      Vancouver
          2 Alison     Mathews         4789.00 2003-07-21 00:00:00.000 South      Utown
          3 James      Smith           6678.00 2001-12-01 00:00:00.000 North      Paris
          4 Celia      Rice            5567.00 2006-03-03 00:00:00.000 South      London
          5 Robert     Black           4467.00 2004-07-02 00:00:00.000 East       Newton
          6 Linda      Green           6456.00 2002-05-19 00:00:00.000 East       Calgary
          7 David      Larry           5345.00 2008-03-18 00:00:00.000 West       New York
          8 James      Cat             4234.00 2007-07-17 00:00:00.000 West       Regina
          9 Joan       Act             6123.00 2001-04-16 00:00:00.000 North      Toronto

(9 rows affected)
1>
2> CREATE TABLE title(
3>    id  INTEGER,
4>    job_title VARCHAR(20)
5> );
6> GO
1> INSERT INTO title VALUES (1, 'developer');
2> INSERT INTO title VALUES (1, 'manager');
3> INSERT INTO title VALUES (2, 'tester');
4> INSERT INTO title VALUES (2, 'programmer');
5> INSERT INTO title VALUES (3, 'boss');
6> INSERT INTO title VALUES (4, 'sales');
7> INSERT INTO title VALUES (5, 'market');
8> INSERT INTO title VALUES (6, 'coder');
9> INSERT INTO title VALUES (7, 'tester');
10> INSERT INTO title VALUES (8, 'developer');
11> INSERT INTO title VALUES (9, 'manager');
12> GO

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)

(1 rows affected)
1>
2>
3> SELECT s.first_name
4> FROM employee s
5> INNER JOIN (SELECT ID
6> FROM title
7> WHERE job_title = 'tester') d ON
8> s.ID = d.ID;
9> GO
first_name
----------
Alison
David

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

 








Related examples in the same category

1.Inline view as a column