Create 49-01767-find-the-subtasks-that-did-not-execute.sql

Author: leetlab11

49-01767-find-the-subtasks-that-did-not-execute.sql

@@ -0,0 +1,22 @@
+-- using recursive CTE
+-- calculate subtask_count starting from given number, subtracting 1 till it reaches 1
+-- so subtasks count shouldn't be less than 2, because 2-1 = 1, and 1-1 will become 0
+-- use recursive cte to get all subtaks
+-- in the final query, pull all rows from cte, except the rows in Executed table
+
+with recursive cte as
+    (select task_id, subtasks_count 
+    from Tasks
+    
+    union all
+    
+    select task_id, subtasks_count-1
+    from cte 
+    where subtasks_count > 1)
+
+select task_id, subtasks_count as subtask_id 
+from cte
+where (task_id, subtasks_count) not in (select * 
+                                        from Executed)
+
+-- google- 1