Introduction
UNIQUE
NOT NULL
CHECK
DEFAULT
Instruction
Alright, excellent. Now we have a small surprise for you. Do you remember sequences from the previous part of our course? We promised we would tell you how to link them to columns - and here we go! We use the DEFAULT constraint:
CREATE TABLE board_game (
id DEFAULT nextval('my_sequence') PRIMARY KEY
);
Not very complicated, right?
Exercise
Ok, first of all we need a sequence. Just to remind you: a sequence with the name my_sequence which starts at 10 and adds 2 each time would look like this:
CREATE SEQUENCE my_sequence START WITH 10 INCREMENT BY 2;
Now, create a sequence called id_seq which starts at 1 and increments by 1.
Stuck? Here's a hint!
Type
CREATE SEQUENCE id_seq START WITH 1 INCREMENT BY 1;
