в 13:45, 26 мая 2010

2010-05-26T13:45:56Z

Admin: 1 версия

2010-05-26T10:13:53Z

1 версия

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==Nested for loop==



<source lang="sql">

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=# CREATE TABLE "subjects" (
postgres(# "id" integer NOT NULL,
postgres(# "subject" text,
postgres(# "location" text,
postgres(# Constraint "subjects_pkey" Primary Key ("id")
postgres(# );
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "subjects_pkey" for table "subjects"
CREATE TABLE
postgres=#
postgres=# insert into subjects values (0, "Arts", "Creativity St");
INSERT 0 1
postgres=# insert into subjects values (1, "Business", "Productivity Ave");
INSERT 0 1
postgres=# insert into subjects values (2, "Children", "Books Kids Ct");
INSERT 0 1
postgres=# insert into subjects values (3, "Classics", "Academic Rd");
INSERT 0 1
postgres=# insert into subjects values (4, "Computers", "Productivity Ave");
INSERT 0 1
postgres=# insert into subjects values (5, "Cooking", "Creativity St");
INSERT 0 1
postgres=# insert into subjects values (6, "Drama", "Main St");
INSERT 0 1
postgres=# insert into subjects values (7, "Entertainment", "Main St");
INSERT 0 1
postgres=# insert into subjects values (8, "History", "Academic Rd");
INSERT 0 1
postgres=# insert into subjects values (9, "Horror", "Black Raven Dr");
INSERT 0 1
postgres=# insert into subjects values (10, "Mystery", "Black Raven Dr");
INSERT 0 1
postgres=# insert into subjects values (11, "Poetry", "Sunset Dr");
INSERT 0 1
postgres=# insert into subjects values (12, "Religion", "Regina");
INSERT 0 1
postgres=# insert into subjects values (13, "Romance", "Main St");
INSERT 0 1
postgres=# insert into subjects values (14, "Science", "Productivity Ave");
INSERT 0 1
postgres=# insert into subjects values (15, "Science Fiction", "Main St");
INSERT 0 1
postgres=#
postgres=# select * from subjects;
id | subject | location
----+-----------------+------------------
0 | Arts | Creativity St
1 | Business | Productivity Ave
2 | Children | Books Kids Ct
3 | Classics | Academic Rd
4 | Computers | Productivity Ave
5 | Cooking | Creativity St
6 | Drama | Main St
7 | Entertainment | Main St
8 | History | Academic Rd
9 | Horror | Black Raven Dr
10 | Mystery | Black Raven Dr
11 | Poetry | Sunset Dr
12 | Religion | Regina
13 | Romance | Main St
14 | Science | Productivity Ave
15 | Science Fiction | Main St
(16 rows)
postgres=#
postgres=#
postgres=#
postgres=# drop function extract_all_titles2();
DROP FUNCTION
postgres=#
postgres=# CREATE FUNCTION "extract_all_titles2" () RETURNS text AS "
postgres"# DECLARE
postgres"# sub_id INTEGER;
postgres"# text_output TEXT = "" "";
postgres"# sub_title TEXT;
postgres"# row_data books%ROWTYPE;
postgres"# BEGIN
postgres"# FOR i IN 0..15 LOOP
postgres"# SELECT INTO sub_title subject FROM subjects WHERE id = i;
postgres"# text_output = text_output || """" || sub_title || "":"";
postgres"#
postgres"# FOR row_data IN SELECT * FROM books
postgres"# WHERE subject_id = i LOOP
postgres"#
postgres"# text_output := text_output || row_data.title || """";
postgres"#
postgres"# END LOOP;
postgres"# END LOOP;
postgres"# RETURN text_output;
postgres"# END;
postgres"# " LANGUAGE "plpgsql";
CREATE FUNCTION
postgres=#
postgres=# select extract_all_titles2();
extract_all_titles2
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Arts:CBusiness:Children:OracleSql ServerPostgre SQLPythonClassics:2DComputers:Programming PythonLearning PythonPerl CookbookPractical PostgreSQLCooking:Drama:Java by APIEntertainment:History:Horror:JavaC++Mystery:Poetry:Religion:Romance:Science:Science Fiction:JavascriptC#
(1 row)
postgres=#
postgres=#
postgres=# drop table books;
DROP TABLE
postgres=# drop table subjects;
DROP TABLE
postgres=#

</source>

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в 13:45, 26 мая 2010

Admin: 1 версия