Mega Code Archive
An UPDATE statement can only modify data of a single table
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1> CREATE TABLE works_on (emp_no INTEGER NOT NULL,
2> project_no CHAR(4) NOT NULL,
3> job CHAR (15) NULL,
4> enter_date DATETIME NULL)
5>
6> insert into works_on values (1, 'p1', 'analyst', '1997.10.1')
7> insert into works_on values (1, 'p3', 'manager', '1999.1.1')
8> insert into works_on values (2, 'p2', 'clerk', '1998.2.15')
9> insert into works_on values (2, 'p2', NULL, '1998.6.1')
10> insert into works_on values (3, 'p2', NULL, '1997.12.15')
11> insert into works_on values (4, 'p3', 'analyst', '1998.10.15')
12> insert into works_on values (5, 'p1', 'manager', '1998.4.15')
13> insert into works_on values (6, 'p1', NULL, '1998.8.1')
14> insert into works_on values (7, 'p2', 'clerk', '1999.2.1')
15> insert into works_on values (8, 'p3', 'clerk', '1997.11.15')
16> insert into works_on values (7, 'p1', 'clerk', '1998.1.4')
17>
18> select * from works_on
19> 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> -- An UPDATE statement can only modify data of a single table.
3>
4>
5> UPDATE works_on
6> SET job = 'Manager'
7> WHERE emp_no = 2
8> AND project_no = 'p2'
9> GO
(2 rows affected)
1> select * from works_on
2> GO
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 Manager 1998-02-15 00:00:00.000
2 p2 Manager 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> drop table works_on
2> GO
1>
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