ABAP Programs: Modifying multiple entries in a database table

REPORT ZSOURCE1306.
* Work area
TABLES CUSTOMERS.
* Internal table for changed entries
DATA ALL_CUSTOMERS LIKE CUSTOMERS OCCURS 50
WITH HEADER LINE.

* Filling the internal table
SELECT * FROM CUSTOMERS INTO TABLE ALL_CUSTOMERS
WHERE CITY = SPACE.
ALL_CUSTOMERS-ID = ’04295119′.
ALL_CUSTOMERS-NAME = ‘Gray’.
APPEND ALL_CUSTOMERS.
LOOP AT ALL_CUSTOMERS.
ALL_CUSTOMERS-CITY = ‘City unknown’.
MODIFY ALL_CUSTOMERS.
ENDLOOP.
* Modifying the database table with values from the internal table
MODIFY CUSTOMERS FROM TABLE ALL_CUSTOMERS.