diff --git a/Codility/SQL/SqlEventsDelta.sql b/Codility/SQL/SqlEventsDelta.sql new file mode 100644 index 0000000..75c8da5 --- /dev/null +++ b/Codility/SQL/SqlEventsDelta.sql @@ -0,0 +1,17 @@ +-- write your code in PostgreSQL 9.4 +SELECT e1.event_type, (e1.value - e2.value) as value +FROM events e1 +INNER JOIN events e2 ON e1.event_type = e2.event_type +AND e1.time = ( + SELECT temp1.time + from events temp1 + WHERE temp1.event_type = e1.event_type + ORDER BY temp1.time DESC + LIMIT 1) +AND e2.time = ( + SELECT temp2.time + FROM events temp2 + WHERE temp2.event_type = e2.event_type + ORDER BY temp2.time + DESC LIMIT 1 OFFSET 1 +); \ No newline at end of file