Create weather_observation_station_20.sql

Author: erjan

hackerrank_sql_practice/weather_observation_station_20.sql

@@ -0,0 +1,20 @@
+/*
+A median is defined as a number separating the higher half 
+of a data set from the lower half. Query the median of the 
+Northern Latitudes (LAT_N) from STATION and round your answer to  decimal places.
+
+*/
+
+
+with ordered as (
+select LAT_N from station order by LAT_N desc),
+
+total_num as (
+select count(LAT_N) as c from station),
+
+actual_pos as (
+select round(c/2) as x from total_num)
+
+select round(LAT_N,4) from (
+select LAT_N , row_number() over( order by LAT_N desc) as r from ordered )k 
+where r = (select x from actual_pos)