PostgreSQL/Select Query/OFFSET

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Версия от 10:14, 26 мая 2010; Admin (обсуждение | вклад) (1 версия)
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NATURAL JOIN works with LIMIT and OFFSET

postgres=# CREATE TABLE "editions" (
postgres(#      "isbn" text NOT NULL,
postgres(#      "book_id" integer,
postgres(#      "edition" integer,
postgres(#      "publisher_id" integer,
postgres(#      "publication" date,
postgres(#      "type" character(1),
postgres(#      CONSTRAINT "integrity" CHECK (((book_id NOTNULL) AND (edition NOTNULL))),
postgres(#      Constraint "pkey" Primary Key ("isbn")
postgres(# );
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "pkey" for table "editions"
CREATE TABLE
postgres=#
postgres=# insert into editions values("039480001X", 1608,  1,  59,  "1957-03-01", "h");
INSERT 0 1
postgres=# insert into editions values("0451160916", 7808,  1,  75,  "1981-08-01", "p");
INSERT 0 1
postgres=# insert into editions values("0394800753", 1590,  1,  59,  "1949-03-01", "p");
INSERT 0 1
postgres=# insert into editions values("0451198492", 4267,  3,  101, "1999-10-01", "h");
INSERT 0 1
postgres=# insert into editions values("0823015505", 2038,  1,  62,  "1958-01-01", "p");
INSERT 0 1
postgres=# insert into editions values("0596000855", 41473, 2,  113, "2001-03-01", "p");
INSERT 0 1
postgres=#
postgres=# select * from editions;
    isbn    | book_id | edition | publisher_id | publication | type
------------+---------+---------+--------------+-------------+------
 039480001X |    1608 |       1 |           59 | 1957-03-01  | h
 0451160916 |    7808 |       1 |           75 | 1981-08-01  | p
 0394800753 |    1590 |       1 |           59 | 1949-03-01  | p
 0451198492 |    4267 |       3 |          101 | 1999-10-01  | h
 0823015505 |    2038 |       1 |           62 | 1958-01-01  | p
 0596000855 |   41473 |       2 |          113 | 2001-03-01  | p
(6 rows)
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 (1590,  "Java",                  4156, 9);
INSERT 0 1
postgres=# insert into books values (7808,  "Javascript",            1866, 15);
INSERT 0 1
postgres=# insert into books values (1608, "Perl Cookbook",         7806, 4);
INSERT 0 1
postgres=# insert into books values (41473, "Practical PostgreSQL",  1212, 4);
INSERT 0 1
postgres=#
postgres=# select * from books;
  id   |        title         | author_id | subject_id
-------+----------------------+-----------+------------
  1590 | Java                 |      4156 |          9
  7808 | Javascript           |      1866 |         15
  1608 | Perl Cookbook        |      7806 |          4
 41473 | Practical PostgreSQL |      1212 |          4
(4 rows)
postgres=#
postgres=# SELECT isbn, title, publication
postgres-#         FROM editions NATURAL JOIN books AS b (book_id)
postgres-#         ORDER BY publication DESC
postgres-#         LIMIT 5
postgres-#         OFFSET 2;
    isbn    |     title     | publication
------------+---------------+-------------
 039480001X | Perl Cookbook | 1957-03-01
 0394800753 | Java          | 1949-03-01
(2 rows)
postgres=#
postgres=#
postgres=#
postgres=# drop table books cascade;
DROP TABLE
postgres=# drop table editions cascade;
DROP TABLE
postgres=#