Question

TABLE tab

sl_no    name    marks status 
  1      dude     33     y
  2      dudz     38     y
  3      duda     44     y
  4      dudi     55     y



select marks from tab where name ='dudi';

But my question is how to add or subtract a row value[marks]

like i need to add 10 to that selected person’s marks

update tab set marks ='marks'+10 where name ='dudi';

update tab set marks =(select marks from tab where name ='dudi') +10 where name ='dudi';

output

  4      dudi     65     y

but i am not able to add the marks to it..

Answer 1

The first syntax should be correct, just don’t put marks in quote. It should be:
update tab set marks = marks + 10 where name ='dudi';