Define foreign key for a table : FOREIGN KEY « Constraints « PostgreSQL






  1. PostgreSQL
  2. Constraints
  3. FOREIGN KEY

Define foreign key for a table


postgres=#
postgres=# -- Foreign Keys
postgres=#
postgres=# CREATE TABLE products (
postgres(#    product_no integer PRIMARY KEY,
postgres(#    name text,
postgres(#    price numeric
postgres(# );
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "products_pkey" for table "products"
CREATE TABLE
postgres=#
postgres=# CREATE TABLE orders (
postgres(#    order_id integer PRIMARY KEY,
postgres(#    product_no integer REFERENCES products (product_no),
postgres(#    quantity integer
postgres(# );
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "orders_pkey" for table "orders"
CREATE TABLE
postgres=#
postgres=# drop table products cascade;
NOTICE:  drop cascades to constraint orders_product_no_fkey on table orders
DROP TABLE
postgres=# drop table orders cascade;
DROP TABLE
postgres=#
postgres=#








Related examples in the same category

1.Reference two two columns as foreign key column
2.Adding constraints (FOREIGN KEY) to a table
3.Adding a constraint to an existing table: add foreign key to table
4.Create FOREIGN KEY
5.Using foreign keys
6.ALTER TABLE employee ADD FOREIGN KEY (group_id) REFERENCES product_groups