SQL Server/T-SQL/Table Joins/Cross Join
ANSI join syntax for cross join
<source lang="sql">
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> 6> -- ANSI join syntax: 7> 8> SELECT * FROM works_on CROSS JOIN project 9> WHERE works_on.project_no = "p3" 10> GO emp_no project_no job enter_date project_no project_name budget
---------- --------------- ----------------------- ---------- --------------- ------------------------
1 p3 manager 1999-01-01 00:00:00.000 p1 Search Engine 120000
1 p3 manager 1999-01-01 00:00:00.000 p3 SQL 186500
4 p3 analyst 1998-10-15 00:00:00.000 p1 Search Engine 120000
4 p3 analyst 1998-10-15 00:00:00.000 p3 SQL 186500
8 p3 clerk 1997-11-15 00:00:00.000 p1 Search Engine 120000
8 p3 clerk 1997-11-15 00:00:00.000 p3 SQL 186500
(6 rows affected) 1> 2> drop table works_on 3> drop table project 4> GO 1>
</source>
Cartesian Product: cross join
<source lang="sql">
1> 2> CREATE TABLE employee (emp_no INTEGER NOT NULL, 3> emp_fname CHAR(20) NOT NULL, 4> emp_lname CHAR(20) NOT NULL, 5> dept_no CHAR(4) NULL) 6> 7> insert into employee values(1, "Matthew", "Smith", "d3") 8> insert into employee values(2, "Ann", "Jones", "d3") 9> insert into employee values(3, "John", "Barrimore","d1") 10> insert into employee values(4, "James", "James", "d2") 11> insert into employee values(5, "Elsa", "Bertoni", "d2") 12> insert into employee values(6, "Elke", "Hansel", "d2") 13> insert into employee values(7, "Sybill", "Moser", "d1") 14> 15> select * from employee 16> GO (1 rows affected) (1 rows affected) (1 rows affected) (1 rows affected) (1 rows affected) (1 rows affected) (1 rows affected) emp_no emp_fname emp_lname dept_no
-------------------- -------------------- -------
1 Matthew Smith d3
2 Ann Jones d3
3 John Barrimore d1
4 James James d2
5 Elsa Bertoni d2
6 Elke Hansel d2
7 Sybill Moser d1
(7 rows affected) 1> 2> 3> CREATE TABLE department(dept_no CHAR(4) NOT NULL, 4> dept_name CHAR(25) NOT NULL, 5> location CHAR(30) NULL) 6> 7> insert into department values ("d1", "developer", "Dallas") 8> insert into department values ("d2", "tester", "Seattle") 9> insert into department values ("d3", "marketing", "Dallas") 10> 11> select * from department 12> GO (1 rows affected) (1 rows affected) (1 rows affected) dept_no dept_name location
------------------------- ------------------------------
d1 developer Dallas d2 tester Seattle d3 marketing Dallas (3 rows affected) 1> 2> 3> -- Cartesian Product 4> 5> -- ANSI join syntax: 6> 7> SELECT * FROM employee CROSS JOIN department 8> GO emp_no emp_fname emp_lname dept_no dept_no dept_name location
-------------------- -------------------- ------- ------- ------------------------- ------------------
1 Matthew Smith d3 d1 developer Dallas
2 Ann Jones d3 d1 developer Dallas
3 John Barrimore d1 d1 developer Dallas
4 James James d2 d1 developer Dallas
5 Elsa Bertoni d2 d1 developer Dallas
6 Elke Hansel d2 d1 developer Dallas
7 Sybill Moser d1 d1 developer Dallas
1 Matthew Smith d3 d2 tester Seattle
2 Ann Jones d3 d2 tester Seattle
3 John Barrimore d1 d2 tester Seattle
4 James James d2 d2 tester Seattle
5 Elsa Bertoni d2 d2 tester Seattle
6 Elke Hansel d2 d2 tester Seattle
7 Sybill Moser d1 d2 tester Seattle
1 Matthew Smith d3 d3 marketing Dallas
2 Ann Jones d3 d3 marketing Dallas
3 John Barrimore d1 d3 marketing Dallas
4 James James d2 d3 marketing Dallas
5 Elsa Bertoni d2 d3 marketing Dallas
6 Elke Hansel d2 d3 marketing Dallas
7 Sybill Moser d1 d3 marketing Dallas
(21 rows affected) 1> 2> drop table employee 3> drop table department 4> GO 1>
</source>
Cross join tables
<source lang="sql">
10> create table employee( 11> ID int, 12> name nvarchar (10), 13> salary int ) 14> 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> insert into employee (ID, name, salary) values (2, "Robert", 4321) 2> GO 1> insert into employee (ID, name, salary) values (3, "Celia", 5432) 2> GO 1> insert into employee (ID, name, salary) values (4, "Linda", 3456) 2> GO 1> insert into employee (ID, name, salary) values (5, "David", 7654) 2> GO 1> insert into employee (ID, name, salary) values (6, "James", 4567) 2> GO 1> insert into employee (ID, name, salary) values (7, "Alison", 8744) 2> GO 1> insert into employee (ID, name, salary) values (8, "Chris", 9875) 2> GO 1> insert into employee (ID, name, salary) values (9, "Mary", 2345) 2> GO 1> 2> insert into job(ID, title, averageSalary) values(1,"Developer",3000) 3> GO 1> insert into job(ID, title, averageSalary) values(2,"Tester", 4000) 2> GO 1> insert into job(ID, title, averageSalary) values(3,"Designer", 5000) 2> GO 1> insert into job(ID, title, averageSalary) values(4,"Programmer", 6000) 2> GO 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
1> select * from job; 2> GO ID title averageSalary
---------- -------------
1 Developer 3000
2 Tester 4000
3 Designer 5000
4 Programmer 6000
1> 2> SELECT TOP 5 e.ID, e.Name , j.title 3> FROM Employee e CROSS JOIN job j 4> ORDER BY j.ID 5> GO ID Name title
---------- ----------
1 Jason Developer
2 Robert Developer
3 Celia Developer
4 Linda Developer
5 David Developer
1> 2> 3> drop table employee; 4> drop table job; 5> GO 1>
</source>
