How to add a positive integer constraint to a integer column in MySQL?

Question

How can we add a constraint which enforces a column to have only positive values.

Tried the following mysql statement but it doesn\'t work

create tab         


        

Answer 1

just use unsigned to allow only positive values.

CREATE TABLE hello 
(
    world int unsigned
);

• SQLFiddle demo

uncomment the line and you will see the error saying: Data truncation: Out of range value for column 'world' at row 1: