SQL implementation has data to update, no insert

First build the table:

CREATE TABLE Lxt_user3 (
user_id int unsigned NOT NULL primary key auto_increment comment ' user ID ',
qq_open_id varch AR (+) unique,---------------The table must have a unique field, otherwise the following SQL statement will not perform as expected
role_id int unsigned not NULL,
Category _id int unsigned,
status int unsigned,
name varchar (default '),
img varchar (+) default ',
password var char (+) default ',
Salt varchar (4) Default ',
Sex int,
email varchar (+) Default ',
Telephone varchar (20 Default ',
Address varchar (+) default ',
Navigation varchar (+) Default ',
Simple_menu varchar (1000) Default ',
Dashboard text,
Reg_ip varchar (0) Default ',
reg_time int unsigned default,
Last_login_time int unsigned default 0,
lostpw_time int unsigned default 0,
Weixinid int,
Last_read_time varchar ($) Default ' ,
Qqnumber int,
Realname varchar (+) Default ',
Position varchar (default '
) Engine=myisam default Charset=utf8 comment ' user table ';

A key SQL statement:

$sql = "INSERT into Lxt_user3 SET realname= ' $realname ', role_id= ' $role _id ', sex= ' $sex ', name= ' $name ', qq_open_id= ' $qq _ open_id ' on DUPLICATE KEY UPDATE realname= ' $realname ', role_id= ' $role _id ', sex= ' $sex ', name= ' $name ', qq_open_id= ' $qq _ Open_id ' ";

SQL implementation has data to update, no insert