Swap Salary

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.

Example:


Table: Salary

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

Output

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

Approach

Mysql: Using case statement

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

Mysql: Using IF

UPDATE salary SET sex = IF(sex='m''f''m');

Oracle: Using case statement

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

Oracle: Using decode

update salary set sex=decode(sex,'m','f','f','m')


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