Nonsense. poj wrote

my $sql = 'SELECT ID,DISABLED
           FROM EmployerJobs
           WHERE Username = ?
             AND UserPassword = ?
             AND Userid = ?
             AND Disabled <> ?';
[download]

which is valid SQL. Whereas you wrote

my $sql = 'SELECT ID,Disabled
           FROM EmployerJobs
           WHERE Username = ?
             AND Password = ?
             AND USERID = ?
             AND Disabled = <> ?';
[download]

which is not.