Update and rename leetcode_196.sql to leetcode_196.md

Author: developer-Akhil

leetcode_196.md

@@ -0,0 +1,17 @@
+# Description
+196. Delete Duplicate Emails
+
+https://leetcode.com/problems/delete-duplicate-emails/description/
+
+# Solution
+-- ------- Approach 2
+```
+delete from leetcode.person_196 where id not in(
+select * from (select min(id) as id from leetcode.person_196 group by email) as p);
+```
+
+-- ------- Approach 2
+```
+with my_cte as (select min(id) as id from leetcode.person_196 group by email)
+delete from leetcode.person_196 where id not in (select id from my_cte); 
+```