Update swap-salary.sql

kamyu104 · web-flow · commit 921e437182bb · 2017-10-03T13:38:34.000+08:00
diff --git a/MySQL/swap-salary.sql b/MySQL/swap-salary.sql
@@ -1,4 +1,23 @@
 # Time:  O(n)
 # Space: O(1)
 
+# 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 = IF(sex = 'm', 'f', 'm')
