We do not have to retrieve data first and manipulate it before executing the SQL UPDATE.

Avoiding that work requires an extra call to DB2.

Below example dynamically retrieve a row, and update the Column value.

suppose an employee is to be given a 10% raise. You could select the employee’s salary, add 10% to the value, and then use the new value in an SQL UPDATE statement. Instead, the Update statement should look like this:
UPDATE EMP
SET SALARY = SALARY * 1.1
WHERE EMPNO = 1000

The way coding above is good practice.