SQL Server/T-SQL/Table Joins/Cross Join — различия между версиями

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Текущая версия на 10:19, 26 мая 2010

ANSI join syntax for cross join

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>



Cartesian Product: cross join

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>



Cross join tables

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>