4D Doc Center : table

4D v12.1

table_constraint



	Command table_constraint{primary_key_definition \| foreign_key_definition}

A table_constraint restricts the values that a table can store.You can either pass a primary_key_definition or a foreign_key_definition. The primary_key_definition sets the primary key for the table and the foreign_key_definition is used to set the foreign key (which matches the primary key of another table).

This example sets Name as the primary key field:

CREATE TABLE ACTOR_FANS
(ID INT32, Name VARCHAR NOT NULL UNIQUE);