add 627

Author: milangrahovac

627-swap_salary.sql

@@ -0,0 +1,31 @@
+-- 627. 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 query and no intermediate temp table.
+
+-- For example:
+
+-- | id | name | sex | salary |
+-- |----|------|-----|--------|
+-- | 1  | A    | m   | 2500   |
+-- | 2  | B    | f   | 1500   |
+-- | 3  | C    | m   | 5500   |
+-- | 4  | D    | f   | 500    |
+
+-- After running your query, 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    |
+
+
+UPDATE salary
+SET
+    sex = CASE sex
+        WHEN 'm' THEN 'f'
+        ELSE 'm'
+    END;