PHP: msqyl join self and LIKE query

Question

I use below code but not work

SELECT `oldTb`.`userId`
FROM `user` AS oldTb JOIN
     `user` AS newTb
WHERE `newTb`.`userPrivate` LIKE "%,`oldTb`.`userId`,%"
GROUP BY `userId`

Actually, i want get result of users when userPrivate column have ,ID, of users from self table

Example:

userId ---- userPrivate    
1  ---- ,0,    
2 ---- ,0,    
3 ---- ,1,    
4 ---- ,1,3,    
5 ---- ,3,

Now have to result is :

1 and 3