diff --git a/Problem1.sql b/Problem1.sql new file mode 100644 index 0000000..3bf0ae5 --- /dev/null +++ b/Problem1.sql @@ -0,0 +1,7 @@ +# Write your MySQL query statement below +SELECT DISTINCT l1.num AS 'ConsecutiveNums' +FROM Logs l1, logs l2, Logs l3 +WHERE l1.id = l2.id - 1 +AND l2.id = l3.id - 1 +AND l1.num = l2.num +AND l2.num = l3.num; \ No newline at end of file diff --git a/Problem2.sql b/Problem2.sql new file mode 100644 index 0000000..e4ce5c3 --- /dev/null +++ b/Problem2.sql @@ -0,0 +1,14 @@ +# Write your MySQL query statement below +WITH CTE AS ( + SELECT p.passenger_id, p.arrival_time, MIN(b.arrival_time) AS 'btime' + FROM Passengers p + INNER JOIN Buses b + ON p.arrival_time <= b.arrival_time + GROUP BY passenger_id +) +SELECT b.bus_id, COUNT(c.btime) AS 'passengers_cnt' +FROM Buses b +LEFT JOIN CTE c +ON c.btime = b.arrival_time +GROUP BY b.bus_id +ORDER BY b.bus_id; \ No newline at end of file diff --git a/Problem3.sql b/Problem3.sql new file mode 100644 index 0000000..ca18bc8 --- /dev/null +++ b/Problem3.sql @@ -0,0 +1,5 @@ +# Write your MySQL query statement below +SELECT activity_date AS 'day', COUNT(DISTINCT user_id) AS 'active_users' +FROM Activity +WHERE activity_date >= '2019-06-28' AND activity_date <= '2019-07-27' +GROUP BY activity_date; \ No newline at end of file