Re: providing a single line for multiple records from a table

[Rick James]

select  a.rollno,a.name,a.dt_birth,a.dt_appt,
       b.de_name,sum(case when c.code=1101 then amount else 0 end) as basic,
        sum(case when c.code=6270 then amount else 0 end ) as allowance
    from  empl a,saldesg b , salamount c
    where  a.rollno = c.rollno
      and  a.desg_code = b.de_code ;

-->

select  a.rollno,a.name,a.dt_birth,a.dt_appt,
        b.de_name, 
      ( SELECT  sum(amount)
            FROM  salamount
            WHERE  code=1101
              AND  rollno = a.rollno ) as basic, 
      ( SELECT  sum(amount)
            FROM  salamount
            WHERE  code=6270
              AND  rollno = a.rollno ) as allowance
    from  empl a
    JOIN  saldesg b ON a.desg_code = b.de_code ;

It would help to have one of these compound indexes on salamount:
INDEX(rollno, code)
or
INDEX(code, rollno)