в 13:45, 26 мая 2010

2010-05-26T13:45:56Z

Admin: 1 версия

2010-05-26T10:13:55Z

1 версия

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==ROWTYPE assign through "select into"==



<source lang="sql">

postgres=#
postgres=#
postgres=# CREATE TABLE employee (
postgres(# ID int,
postgres(# name varchar(10),
postgres(# salary real,
postgres(# start_date date,
postgres(# city varchar(10),
postgres(# region char(1)
postgres(# );
CREATE TABLE
postgres=#
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (1, "Jason", 40420, "02/01/94", "New York", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (2, "Robert",14420, "01/02/95", "Vancouver","N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (3, "Celia", 24020, "12/03/96", "Toronto", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (4, "Linda", 40620, "11/04/97", "New York", "N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (5, "David", 80026, "10/05/98", "Vancouver","W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (6, "James", 70060, "09/06/99", "Toronto", "N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (7, "Alison",90620, "08/07/00", "New York", "W");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (8, "Chris", 26020, "07/08/01", "Vancouver","N");
INSERT 0 1
postgres=# insert into employee (ID, name, salary, start_date, city, region)
postgres-# values (9, "Mary", 60020, "06/09/02", "Toronto", "W");
INSERT 0 1
postgres=#
postgres=# select * from employee;
id | name | salary | start_date | city | region
----+--------+--------+------------+-----------+--------
1 | Jason | 40420 | 1994-02-01 | New York | W
2 | Robert | 14420 | 1995-01-02 | Vancouver | N
3 | Celia | 24020 | 1996-12-03 | Toronto | W
4 | Linda | 40620 | 1997-11-04 | New York | N
5 | David | 80026 | 1998-10-05 | Vancouver | W
6 | James | 70060 | 1999-09-06 | Toronto | N
7 | Alison | 90620 | 2000-08-07 | New York | W
8 | Chris | 26020 | 2001-07-08 | Vancouver | N
9 | Mary | 60020 | 2002-06-09 | Toronto | W
(9 rows)
postgres=#
postgres=# CREATE FUNCTION "get_data" (integer) RETURNS text AS "
postgres"# DECLARE
postgres"# -- Declare an alias for the function argument,
postgres"# eid ALIAS FOR $1;
postgres"# found_employee employee%ROWTYPE;
postgres"# BEGIN
postgres"# SELECT INTO found_employee * FROM employee WHERE id = eid;
postgres"# RETURN found_employee.name || "" "" || found_employee.city;
postgres"# END;
postgres"# " LANGUAGE "plpgsql";
CREATE FUNCTION
postgres=#
postgres=# select get_data(id) from employee;
get_data
------------------
Jason New York
Robert Vancouver
Celia Toronto
Linda New York
David Vancouver
James Toronto
Alison New York
Chris Vancouver
Mary Toronto
(9 rows)
postgres=#
postgres=# drop function get_data (integer);
DROP FUNCTION
postgres=# drop table employee;
DROP TABLE
postgres=#
postgres=#
postgres=#

</source>

==Using the FOR loop with %ROWTYPE==



<source lang="sql">

postgres=#
postgres=#
postgres=# CREATE TABLE "books" (
postgres(# "id" integer NOT NULL,
postgres(# "title" text NOT NULL,
postgres(# "author_id" integer,
postgres(# "subject_id" integer,
postgres(# Constraint "books_id_pkey" Primary Key ("id")
postgres(# );
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "books_id_pkey" for table "books"
CREATE TABLE
postgres=#
postgres=#
postgres=# insert into books values (7808, "Java", 4156, 9);
INSERT 0 1
postgres=# insert into books values (4513, "Javascript", 1866, 15);
INSERT 0 1
postgres=# insert into books values (4267, "C#", 2001, 15);
INSERT 0 1
postgres=# insert into books values (1608, "Oracle", 1809, 2);
INSERT 0 1
postgres=# insert into books values (1590, "Sql Server", 1809, 2);
INSERT 0 1
postgres=# insert into books values (25908, "Postgre SQL", 15990, 2);
INSERT 0 1
postgres=# insert into books values (1501, "Python", 2031, 2);
INSERT 0 1
postgres=# insert into books values (190, "Java by API", 16, 6);
INSERT 0 1
postgres=# insert into books values (1234, "2D", 25041, 3);
INSERT 0 1
postgres=# insert into books values (2038, "C", 1644, 0);
INSERT 0 1
postgres=# insert into books values (156, "C++", 115, 9);
INSERT 0 1
postgres=# insert into books values (41473, "Programming Python", 7805, 4);
INSERT 0 1
postgres=# insert into books values (41477, "Learning Python", 7805, 4);
INSERT 0 1
postgres=# insert into books values (41478, "Perl Cookbook", 7806, 4);
INSERT 0 1
postgres=# insert into books values (41472, "Practical PostgreSQL", 1212, 4);
INSERT 0 1
postgres=#
postgres=# select * from books;
id | title | author_id | subject_id
-------+----------------------+-----------+------------
7808 | Java | 4156 | 9
4513 | Javascript | 1866 | 15
4267 | C# | 2001 | 15
1608 | Oracle | 1809 | 2
1590 | Sql Server | 1809 | 2
25908 | Postgre SQL | 15990 | 2
1501 | Python | 2031 | 2
190 | Java by API | 16 | 6
1234 | 2D | 25041 | 3
2038 | C | 1644 | 0
156 | C++ | 115 | 9
41473 | Programming Python | 7805 | 4
41477 | Learning Python | 7805 | 4
41478 | Perl Cookbook | 7806 | 4
41472 | Practical PostgreSQL | 1212 | 4
(15 rows)
postgres=#
postgres=#
postgres=# -- Using the FOR loop with %ROWTYPE
postgres=#
postgres=# CREATE FUNCTION extract_title (integer) RETURNS text AS "
postgres"# DECLARE
postgres"#
postgres"# -- Declare an alias for function argument.
postgres"# sub_id ALIAS FOR $1;
postgres"#
postgres"# -- Declare a variable to hold book titles and set its default
postgres"# -- value to a new line.
postgres"# text_output TEXT :=""\n"";
postgres"#
postgres"# -- Declare a variable to hold rows from the
postgres"# -- books table.
postgres"# row_data books%ROWTYPE;
postgres"#
postgres"# BEGIN
postgres"#
postgres"# -- Iterate through the results of a query.
postgres"# FOR row_data IN SELECT * FROM books
postgres"# WHERE subject_id = sub_id ORDER BY title LOOP
postgres"#
postgres"# -- Insert the title of a matching book into the text_output variable.
postgres"# text_output := text_output || row_data.title || ""\n"";
postgres"# END LOOP;
postgres"#
postgres"# -- Return the list of books.
postgres"# RETURN text_output;
postgres"# END;
postgres"# " LANGUAGE "plpgsql";
ERROR: function "extract_title" already exists with same argument types
postgres=#
postgres=#
postgres=# SELECT extract_title(2);
extract_title
---------------
Sql Server
(1 row)
postgres=#
postgres=#
postgres=# drop table books;
DROP TABLE
postgres=#
postgres=#

</source>

==Using the %ROWTYPE attribute==



<source lang="sql">

postgres=#
postgres=#
postgres=# CREATE TABLE "authors" (
postgres(# "id" integer NOT NULL,
postgres(# "last_name" text,
postgres(# "first_name" text,
postgres(# Constraint "authors_pkey" Primary Key ("id")
postgres(# );
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "authors_pkey" for table "authors"
CREATE TABLE
postgres=#
postgres=#
postgres=# insert into authors values (1111, "Martin", "Jason");
INSERT 0 1
postgres=# insert into authors values (1212, "Worsley", "Robert");
INSERT 0 1
postgres=# insert into authors values (15990, "Mathews", "John");
INSERT 0 1
postgres=# insert into authors values (25041, "Smith", "Williams");
INSERT 0 1
postgres=# insert into authors values (16, "Alcott", "May");
INSERT 0 1
postgres=# insert into authors values (4156, "King", "Stephen");
INSERT 0 1
postgres=# insert into authors values (1866, "Herbert", "Margaret");
INSERT 0 1
postgres=# insert into authors values (1644, "Hogarth", "Celia");
INSERT 0 1
postgres=# insert into authors values (2031, "Brown", "Wise");
INSERT 0 1
postgres=# insert into authors values (115, "Poe", "Allen");
INSERT 0 1
postgres=# insert into authors values (7805, "Lutz", "Mark");
INSERT 0 1
postgres=# insert into authors values (7806, "Rice", "Tom");
INSERT 0 1
postgres=# insert into authors values (1533, "Black", "Chris");
INSERT 0 1
postgres=# insert into authors values (1717, "Brite", "Linda");
INSERT 0 1
postgres=# insert into authors values (2112, "Larry", "Edward");
INSERT 0 1
postgres=# insert into authors values (2001, "Clarke", "Alison");
INSERT 0 1
postgres=# insert into authors values (1213, "Green", "Mary");
INSERT 0 1
postgres=#
postgres=# select * from authors;
id | last_name | first_name
-------+-----------+------------
1111 | Martin | Jason
1212 | Worsley | Robert
15990 | Mathews | John
25041 | Smith | Williams
16 | Alcott | May
4156 | King | Stephen
1866 | Herbert | Margaret
1644 | Hogarth | Celia
2031 | Brown | Wise
115 | Poe | Allen
7805 | Lutz | Mark
7806 | Rice | Tom
1533 | Black | Chris
1717 | Brite | Linda
2112 | Larry | Edward
2001 | Clarke | Alison
1213 | Green | Mary
(17 rows)
postgres=#
postgres=#
postgres=#
postgres=# -- Using the %ROWTYPE attribute
postgres=#
postgres=# CREATE FUNCTION get_author (integer) RETURNS text AS "
postgres"# DECLARE
postgres"#
postgres"# -- Declare an alias for the function argument,
postgres"# -- which should be the id of the author.
postgres"# author_id ALIAS FOR $1;
postgres"#
postgres"# found_author authors%ROWTYPE;
postgres"#
postgres"# BEGIN
postgres"# SELECT INTO found_author * FROM authors WHERE id = author_id;
postgres"#
postgres"# -- Return the first
postgres"# RETURN found_author.first_name || "" "" || found_author.last_name;
postgres"#
postgres"# END;
postgres"# " LANGUAGE "plpgsql";
CREATE FUNCTION
postgres=#
postgres=# -- Results of the new get_author() function
postgres=#
postgres=# SELECT get_author(1212);
get_author
----------------
Robert Worsley
(1 row)
postgres=#
postgres=#
postgres=# drop table authors;
DROP TABLE
postgres=#
postgres=#

</source>

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в 13:45, 26 мая 2010

Admin: 1 версия