FOREIGN KEY « Constraints « PostgreSQL






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