sql - Update using subquery in plsql block -

if comm null, need update comm value salary, 1100, not getting updated.

my data is:

sal        comm     9000    800 2975    800 3000    800 1100     3000    800 

my code is:

declare   cursor c3 select sal,comm,ename emp deptno=20   update of comm; begin   c in c3   loop     if c.comm null           update emp set comm=(select c.sal emp e e.comm=c.comm )       current of c3;     end if;   end loop; end; 

please give me opinion on this.

this line:

update emp set comm=(select c.sal emp e e.comm=c.comm ) 

... not work. know c.comm null, you're trying find record on emp matching value, , can't use equality test null. won't work if there more 1 record comm null - in case, of possible sal values use?

you don't need query emp again @ all; select pointless, if worked, since can data row you're updating:

update emp set comm = sal current of c3; 

you remove if test changing cursor null values:

cursor c3 select sal,comm,ename   emp   deptno=20   , comm null   update of comm; 

but other answers have pointed out, don't need in pl/sql @ all, simple sql update suffice.