SQL3 Submitted

Problem1.sql

@@ -0,0 +1,5 @@
+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

Problem2.sql

@@ -0,0 +1,7 @@
+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 p.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 

Problem3.sql

@@ -0,0 +1,5 @@
+SELECT activity_date as 'day', Count(Distinct user_id) as 'active_users'
+from activity
+where activity_date>'2019-06-27'
+And activity_date<='2019-07-27'
+group by activity_date

Problem4.sql

@@ -0,0 +1,15 @@
+CREATE PROCEDURE PivotProducts()
+BEGIN
+
+SET SESSION GROUP_CONCAT_MAX_LEN = 1000000;
+    SELECT GROUP_CONCAT(DISTINCT CONCAT('SUM(IF(store = "',store , '" , price , null)) as ' , store))
+    INTo @sql from products;
+
+    SET @sql = CONCAT('SELECT product_id ,' , @sql , ' from products GROUP by 1');
+
+
+    PREPARE statement from @sql;
+    EXECUTE statement;
+    DEALLOCATE PREPARE STATEMENT;
+
+END