Update retrieving-first-instance-of-change-event-using-conditional_change_event.md

Author: structured-query-language

retrieving-first-instance-of-change-event-using-conditional_change_event.md

@@ -1,25 +1,38 @@
 # Retrieving first instance of change event using conditional_change_event
 
-`CONDITIONAL_CHANGE_EVENT` is a versatile Snowflake function that returns a window event number for each row when the value of the expression is different from the value in the previous row.
+Conditional Change Event (`CONDITIONAL_CHANGE_EVENT`) is a versatile Snowflake function that returns a window event number for each row when the value of the expression is different from the value in the previous row.
 
 This can be a very powerful function to use when analyzing events data or time-series data. For e.g. if you need to retrieve the first `update_date` by Support Engineer per Case Status change in the following data:
 
 |![Screen Shot 2024-12-04 at 9 09 14 PM](https://github.com/user-attachments/assets/bef4184b-5bbf-4a32-b95c-51666a2e4b09)|
 |:--:|
-|We need to retrieve the first `status_date` by Support Engineer per Case Status change|
+|We need the first `status_date` by Support Engineer per Case Status change|
 
 ```sql
 with support_cases as (
   select *
   , conditional_change_event (status || support_engineer)
-      over (partition by case_number order by update_date asc) as dense_sequence
+      over (partition by case_number order by update_date asc) as change_rank_number
+  from support_case
+);
+```
+|![Screen Shot 2024-12-05 at 6 42 19 PM](https://github.com/user-attachments/assets/53f8ed05-4681-4154-a451-7cda5ee3c254)|
+|:--:|
+|`change_rank_number` increases each time the Support Engineer + Status combination changes|
+
+
+```sql
+with support_cases as (
+  select *
+  , conditional_change_event (status || support_engineer)
+      over (partition by case_number order by update_date asc) as change_rank_number
   from support_case
 )
 select * from support_cases
-qualify row_number() over (partition by case_number, dense_sequence order by update_date)  = 1;
+qualify row_number() over (partition by case_number, change_rank_number order by update_date)  = 1;
 ```
 
-|![Screen Shot 2024-12-05 at 8 12 20 AM](https://github.com/user-attachments/assets/fc8661f4-4bea-4a15-8bea-5cdcc65a67ea)|
+|![Screen Shot 2024-12-05 at 7 23 50 PM](https://github.com/user-attachments/assets/f10f24c8-738d-4fa5-8aad-cfc99740397f)|
 |:--:|
-|First `status_date` by Support Engineer per Case Status chang|
+|first `status_date` by Support Engineer per Case Status change|