Mega Code Archive

 

Categories / PostgreSQL / Constraints

 

Adding a constraint to an existing table

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=# -- Adding a constraint to an existing table postgres=# postgres=# ALTER TABLE books ADD CONSTRAINT legal_subjects postgres-#                    FOREIGN KEY (subject_id) postgres-#                    REFERENCES subjects (id); ALTER TABLE postgres=# postgres=# drop table books; DROP TABLE postgres=#