Skip to Content
PostgreSQL 10 Administration Cookbook - Fourth Edition
book

PostgreSQL 10 Administration Cookbook - Fourth Edition

by Simon Riggs, Gianni Ciolli
May 2018
Intermediate to advanced content levelIntermediate to advanced
576 pages
30h 25m
English
Packt Publishing
Content preview from PostgreSQL 10 Administration Cookbook - Fourth Edition

Getting ready

We'll use the following simple database to understand and investigate them. There are two tables, as follows:

CREATE TABLE orders (orderid integer PRIMARY KEY);CREATE TABLE orderlines (orderid integer,lineid smallint,PRIMARY KEY (orderid, lineid));

Now, we add a link between them to enforce what is known as Referential Integrity, as follows:

ALTER TABLE orderlines ADD FOREIGN KEY (orderid)REFERENCES orders (orderid);

If we try to drop the referenced table, we get the following message:

DROP TABLE orders;ERROR: cannot drop table orders because other objects depend on itDETAIL: constraint orderlines_orderid_fkey on table orderlines depends on table ordersHINT: Use DROP ... CASCADE to drop the dependent objects too.

Be very careful! ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

PostgreSQL 13 Cookbook

PostgreSQL 13 Cookbook

Vallarapu Naga Avinash Kumar
PostgreSQL 9 Administration Cookbook - Second Edition

PostgreSQL 9 Administration Cookbook - Second Edition

Simon Riggs, GIANNI CIOLLI, Hannu Krosing, Gabriele Bartolini

Publisher Resources

ISBN: 9781788474924Supplemental Content