Question

I have “Customer” table:

CREATE TABLE Customer
(
    ID INTEGER NOT NULL DEFAULT 0,
    Username CHAR(50) NOT NULL,
    Password CHAR(100) NOT NULL,
    LastName CHAR(20) NOT NULL,
    PhoneNumber BIGINT NOT NULL,
    MobileNumber BIGINT NOT NULL,
    PRIMARY KEY (ID)
) 
;

I used char for password type, is this right? And for mobile number I used bigint, is this right? If not what should I do ? And what is the SQL statement for it? Thanks.

Answer 1

As these fields will all be variable lengths you should definitely use VARCHAR instead of CHAR for ‘Username’, ‘Password’ & ‘Lastname’. If you have limits on the lengths these then you can always limit the VARCHAR type to that limit.

As for ‘PhoneNumber’ & ‘MobileNumber’, you won’t be performing any calculations with these values, so there’s no reason not to store them as VARCHAR, not to mention that telephone number often contain a 0 as the first character which cannot be stored as an INT of any kind.

Something like:

CREATE TABLE `Customer` (
 `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
 `Username` varchar(255) NOT NULL DEFAULT '',
 `Password` varchar(255) NOT NULL DEFAULT '',
 `LastName` varchar(255) NOT NULL DEFAULT '',
 `PhoneNumber` varchar(100) DEFAULT NULL,
 `MobileNumber` varchar(100) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;