Swapping column values in Oracle

Question

I was solving one of the puzzles and came across swapping column values using DML queries:

SELECT * FROM TEMP_TABLE;
ID1, ID2
--------
20, 15
20, 15
20, 15
         


        

Answer 1

CREATE TABLE Names
(
F_NAME VARCHAR(22),
L_NAME VARCHAR(22)
);

INSERT INTO Names VALUES('Ashutosh', 'Singh'),('Anshuman','Singh'),('Manu', 'Singh');

UPDATE Names N1 , Names N2 SET N1.F_NAME = N2.L_NAME , N1.L_NAME = N2.F_NAME 
WHERE N1.F_NAME = N2.F_NAME;

SELECT * FROM Names;