I am trying to update a database via an update query,but I am getting an error that says

```
Error com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'add=null,col=null,wok=null,pcol=null,pwok=null,bio=null where un ='null'' at line 1.

```

I have been trying for hours to figure out what the error is in my SQL Syntax,but I haven't been able to get through.

The update query is:

```
query = "Update users SET em=?, mn=?,add=?,col=?,wok=?,pcol=?,pwok=?,bio=? where un ='"+un+"'";

```

I need help in figuring out the error in my update syntax,Thanks.