Introduction
UNIQUE
NOT NULL
CHECK
DEFAULT
Instruction
Well, the update failed because the new value for the column price didn't meet the criterion, just as we could expect.
Exercise
Let's leave the game community for a while and do a little practice. Create a table salary with the following columns:
employee_id- a unique integer number,monthly- a decimal of up to 10 digits with 2 digits after the decimal point,annual- a decimal of up to 10 digits with 2 digits after the decimal point.
CHECK constraint: the
annual field must equal the
monthly field times 12.
Stuck? Here's a hint!
Type
CREATE TABLE salary ( employee_id int UNIQUE, monthly decimal(10,2), annual decimal(10, 2), CHECK (monthly * 12 = annual) );
