PostgreSQL/Insert Delete Update/DELETE ONLY — различия между версиями

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м (1 версия)
 
(нет различий)

Версия 13:45, 26 мая 2010

DELETE ONLY from parent table

postgres=#
postgres=# -- Creating a child table
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=# CREATE TABLE distinguished_authors (award text)
postgres-#               INHERITS (authors);
CREATE TABLE
postgres=#
postgres=# INSERT INTO distinguished_authors VALUES (1809, "G", "T", "Prize");
INSERT 0 1
postgres=#
postgres=# SELECT * FROM distinguished_authors;
  id  | last_name | first_name | award
------+-----------+------------+-------
 1809 | G         | T          | Prize
(1 row)
postgres=#
postgres=# SELECT * FROM authors;
  id  | last_name | first_name
------+-----------+------------
 1809 | G         | T
(1 row)
postgres=#
postgres=#
postgres=# DELETE FROM ONLY authors WHERE last_name = "G";
DELETE 0
postgres=#
postgres=# SELECT * FROM distinguished_authors;
  id  | last_name | first_name | award
------+-----------+------------+-------
 1809 | G         | T          | Prize
(1 row)
postgres=#
postgres=# SELECT * FROM authors;
  id  | last_name | first_name
------+-----------+------------
 1809 | G         | T
(1 row)
postgres=#
postgres=#
postgres=#
postgres=# drop table distinguished_authors;
DROP TABLE
postgres=# drop table authors;
DROP TABLE
postgres=#