Mega Code Archive
A subquery can be used with comparison operators
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19>
20> CREATE TABLE employee (emp_no INTEGER NOT NULL,
21> emp_fname CHAR(20) NOT NULL,
22> emp_lname CHAR(20) NOT NULL,
23> dept_no CHAR(4) NULL)
24>
25> insert into employee values(1, 'Matthew', 'Smith', 'd3')
26> insert into employee values(2, 'Ann', 'Jones', 'd3')
27> insert into employee values(3, 'John', 'Barrimore','d1')
28> insert into employee values(4, 'James', 'James', 'd2')
29> insert into employee values(5, 'Elsa', 'Bertoni', 'd2')
30> insert into employee values(6, 'Elke', 'Hansel', 'd2')
31> insert into employee values(7, 'Sybill', 'Moser', 'd1')
32>
33> select * from employee
34> GO
Msg 2714, Level 16, State 6, Server RNTSOFT\SQLEXPRESS, Line 20
There is already an object named 'employee' in the database.
1>
2> CREATE TABLE works_on (emp_no INTEGER NOT NULL,
3> project_no CHAR(4) NOT NULL,
4> job CHAR (15) NULL,
5> enter_date DATETIME NULL)
6>
7> insert into works_on values (1, 'p1', 'analyst', '1997.10.1')
8> insert into works_on values (1, 'p3', 'manager', '1999.1.1')
9> insert into works_on values (2, 'p2', 'clerk', '1998.2.15')
10> insert into works_on values (2, 'p2', NULL, '1998.6.1')
11> insert into works_on values (3, 'p2', NULL, '1997.12.15')
12> insert into works_on values (4, 'p3', 'analyst', '1998.10.15')
13> insert into works_on values (5, 'p1', 'manager', '1998.4.15')
14> insert into works_on values (6, 'p1', NULL, '1998.8.1')
15> insert into works_on values (7, 'p2', 'clerk', '1999.2.1')
16> insert into works_on values (8, 'p3', 'clerk', '1997.11.15')
17> insert into works_on values (7, 'p1', 'clerk', '1998.1.4')
18>
19> select * from works_on
20> 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)
emp_no project_no job enter_date
----------- ---------- --------------- -----------------------
1 p1 analyst 1997-10-01 00:00:00.000
1 p3 manager 1999-01-01 00:00:00.000
2 p2 clerk 1998-02-15 00:00:00.000
2 p2 NULL 1998-06-01 00:00:00.000
3 p2 NULL 1997-12-15 00:00:00.000
4 p3 analyst 1998-10-15 00:00:00.000
5 p1 manager 1998-04-15 00:00:00.000
6 p1 NULL 1998-08-01 00:00:00.000
7 p2 clerk 1999-02-01 00:00:00.000
8 p3 clerk 1997-11-15 00:00:00.000
7 p1 clerk 1998-01-04 00:00:00.000
(11 rows affected)
1>
2> -- A subquery can be used with other comparison operators
3>
4> SELECT DISTINCT project_no FROM works_on WHERE emp_no <
5> (SELECT emp_no FROM employee WHERE emp_lname = 'Moser')
6> GO
project_no
----------
p1
p2
p3
(3 rows affected)
1>
2> drop table employee
3> drop table works_on
4> GO
1>
2>
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