SQL Server/T-SQL/Data Set/Union — различия между версиями
Admin (обсуждение | вклад) м (1 версия) |
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Текущая версия на 13:21, 26 мая 2010
Union function demo
<source lang="sql">
1> create table employee( 2> ID int, 3> name nvarchar (10), 4> salary int, 5> start_date datetime, 6> city nvarchar (10), 7> region char (1)) 8> GO 1> 2> insert into employee (ID, name, salary, start_date, city, region) 3> values (1, "Jason", 40420, "02/01/94", "New York", "W") 4> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (2, "Robert",14420, "01/02/95", "Vancouver","N") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (3, "Celia", 24020, "12/03/96", "Toronto", "W") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (4, "Linda", 40620, "11/04/97", "New York", "N") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (5, "David", 80026, "10/05/98", "Vancouver","W") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (6, "James", 70060, "09/06/99", "Toronto", "N") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (7, "Alison",90620, "08/07/00", "New York", "W") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (8, "Chris", 26020, "07/08/01", "Vancouver","N") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (9, "Mary", 60020, "06/09/02", "Toronto", "W") 3> GO (1 rows affected) 1> 2> select * from employee 3> GO ID name salary start_date city region
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1 Jason 40420 1994-02-01 00:00:00.000 New York W 2 Robert 14420 1995-01-02 00:00:00.000 Vancouver N 3 Celia 24020 1996-12-03 00:00:00.000 Toronto W 4 Linda 40620 1997-11-04 00:00:00.000 New York N 5 David 80026 1998-10-05 00:00:00.000 Vancouver W 6 James 70060 1999-09-06 00:00:00.000 Toronto N 7 Alison 90620 2000-08-07 00:00:00.000 New York W 8 Chris 26020 2001-07-08 00:00:00.000 Vancouver N 9 Mary 60020 2002-06-09 00:00:00.000 Toronto W
(9 rows affected) 1> 2> SELECT TOP 3 ID, name FROM Employee where salary = 1000 3> UNION 4> SELECT TOP 3 ID, name FROM Employee where salary = 3000 5> UNION 6> SELECT TOP 3 ID, name FROM Employee where salary > 4000 7> GO ID name
----------
1 Jason 2 Robert 3 Celia
(3 rows affected) 1> 2> 3> drop table employee 4> GO 1>
</source>
Union three data sets
<source lang="sql">
1> create table employee( 2> ID int, 3> name nvarchar (10), 4> salary int, 5> start_date datetime, 6> city nvarchar (10), 7> region char (1)) 8> GO 1> 2> insert into employee (ID, name, salary, start_date, city, region) 3> values (1, "Jason", 40420, "02/01/94", "New York", "W") 4> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (2, "Robert",14420, "01/02/95", "Vancouver","N") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (3, "Celia", 24020, "12/03/96", "Toronto", "W") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (4, "Linda", 40620, "11/04/97", "New York", "N") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (5, "David", 80026, "10/05/98", "Vancouver","W") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (6, "James", 70060, "09/06/99", "Toronto", "N") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (7, "Alison",90620, "08/07/00", "New York", "W") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (8, "Chris", 26020, "07/08/01", "Vancouver","N") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (9, "Mary", 60020, "06/09/02", "Toronto", "W") 3> GO (1 rows affected) 1> 2> select * from employee 3> GO ID name salary start_date city region
---------- ----------- ----------------------- ---------- ------
1 Jason 40420 1994-02-01 00:00:00.000 New York W 2 Robert 14420 1995-01-02 00:00:00.000 Vancouver N 3 Celia 24020 1996-12-03 00:00:00.000 Toronto W 4 Linda 40620 1997-11-04 00:00:00.000 New York N 5 David 80026 1998-10-05 00:00:00.000 Vancouver W 6 James 70060 1999-09-06 00:00:00.000 Toronto N 7 Alison 90620 2000-08-07 00:00:00.000 New York W 8 Chris 26020 2001-07-08 00:00:00.000 Vancouver N 9 Mary 60020 2002-06-09 00:00:00.000 Toronto W
(9 rows affected) 1> 2> SELECT Id, name FROM Employee where id = 1 3> UNION 4> SELECT Id, name FROM Employee where id = 2 5> UNION 6> SELECT id, name FROM Employee where id = 3 7> GO Id name
----------
1 Jason 2 Robert 3 Celia
(3 rows affected) 1> 2> drop table employee 3> GO 1>
</source>
Use Top command with Union
<source lang="sql">
1> create table employee( 2> ID int, 3> name nvarchar (10), 4> salary int, 5> start_date datetime, 6> city nvarchar (10), 7> region char (1)) 8> GO 1> 2> insert into employee (ID, name, salary, start_date, city, region) 3> values (1, "Jason", 40420, "02/01/94", "New York", "W") 4> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (2, "Robert",14420, "01/02/95", "Vancouver","N") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (3, "Celia", 24020, "12/03/96", "Toronto", "W") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (4, "Linda", 40620, "11/04/97", "New York", "N") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (5, "David", 80026, "10/05/98", "Vancouver","W") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (6, "James", 70060, "09/06/99", "Toronto", "N") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (7, "Alison",90620, "08/07/00", "New York", "W") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (8, "Chris", 26020, "07/08/01", "Vancouver","N") 3> GO (1 rows affected) 1> insert into employee (ID, name, salary, start_date, city, region) 2> values (9, "Mary", 60020, "06/09/02", "Toronto", "W") 3> GO (1 rows affected) 1> 2> select * from employee 3> GO ID name salary start_date city region
---------- ----------- ----------------------- ---------- ------
1 Jason 40420 1994-02-01 00:00:00.000 New York W 2 Robert 14420 1995-01-02 00:00:00.000 Vancouver N 3 Celia 24020 1996-12-03 00:00:00.000 Toronto W 4 Linda 40620 1997-11-04 00:00:00.000 New York N 5 David 80026 1998-10-05 00:00:00.000 Vancouver W 6 James 70060 1999-09-06 00:00:00.000 Toronto N 7 Alison 90620 2000-08-07 00:00:00.000 New York W 8 Chris 26020 2001-07-08 00:00:00.000 Vancouver N 9 Mary 60020 2002-06-09 00:00:00.000 Toronto W
(9 rows affected) 1> 2> create table job( 3> ID int, 4> title nvarchar (10), 5> averageSalary int) 6> GO 1> 2> 3> 4> 5> 6> insert into job(ID, title, averageSalary) values(1,"Developer",3000) 7> 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> select * from job 3> GO ID title averageSalary
---------- -------------
1 Developer 3000 2 Tester 4000 3 Designer 5000 4 Programmer 6000
(4 rows affected) 1> 2> 3> SELECT TOP 2 ID FROM Employee 4> UNION 5> SELECT TOP 2 ID FROM Job 6> GO ID
1 2
(2 rows affected) 1> 2> 3> 4> drop table employee 5> drop table job 6> GO 1>
</source>