I want to add constraint using alter command in psql

Question

I have created a table.

But I need to add a constraint for price that price must be greater than 10.

How it can be done using alter command....

Answer 1

You can do this with the check command.

CREATE TABLE test (
  testCol INTEGER DEFAULT 0 NOT NULL
);
ALTER TABLE test
ADD CONSTRAINT ck_value CHECK (testCol > 10);

SQL Fiddle