Data truncation: Data too long for column 'gender' at row 1 出现的原因

create database day15 ;
use day15 ;
create table customer(
	id varchar(100) primary key,
	name varchar(100),
	gender varchar(4),# 1 male  0 female
	birthday date,
	cellphone varchar(20),
	email varchar(40),
	hobby varchar(100),#eat,sleep
	type varchar(40),#vip|normal
	description varchar(255)
);
create database day15 ;
use d