Question

I have a table entity called position. I am storing the value using smallint(2) datatype, where I intend to store the value from 0 to 9 (max). I want to make sure the value is just a single integer and an integer should not be repeated at any cost. There should be a unique value assigned to each id of the position entity in the table ranging from 0 to 9. How do I achieve it? Is there any mysql syntax for that?

I am using MySQL with PHP.

here is the mysql table could someone add me the unique code and show

CREATE TABLE `advertisements` (
`id` int(11) NOT NULL auto_increment,
`title` varchar(255) NOT NULL,
`position` smallint(2) NOT NULL,
`active` tinyint(1) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

is this the correct syntax?

CREATE TABLE `advertisements` (
`id` int(11) NOT NULL auto_increment,
`title` varchar(255) NOT NULL,
`position` smallint(2) NOT NULL UNIQUE,
`active` tinyint(1) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

Answer 1

You must define that column as UNIQUE.

ALTER TABLE `a` ADD UNIQUE (
    `id`
)