easy_627.sql

/*
## easy: 627. Swap Salary

### TASK 

Given a table `salary`, such as the one below, that has m=male and f=female values. Swap all f and m values (i.e., change all f values to m and vice versa) with a **single update statement** and no intermediate temp table.

Note that you must write a single update statement, **DO NOT** write any select statement for this problem.


**Example**:

    | id | name | sex | salary |
    |----|------|-----|--------|
    | 1  | A    | m   | 2500   |
    | 2  | B    | f   | 1500   |
    | 3  | C    | m   | 5500   |
    | 4  | D    | f   | 500    |


After running your update statement, the above salary table should have the following rows:

    | id | name | sex | salary |
    |----|------|-----|--------|
    | 1  | A    | f   | 2500   |
    | 2  | B    | m   | 1500   |
    | 3  | C    | f   | 5500   |
    | 4  | D    | m   | 500    |
*/

-- SOLUTION
UPDATE 
    salary
SET 
    sex = CASE sex
            WHEN 'm' THEN 'f'
            WHEN 'f' THEN 'm'
            END
;