I have table with 3 columns:
ID,
Cancellation_Policy_Type
Cancellation_Policy_Hours.
The query I would like to get to will allow me to select:
- the min Cancellation_Policy_Hours which correspond to the Free Cancellation (if exists)
- if the above doesn’t exist for the specific ID, then I want to check if there is a partially refundable
- if none of the above exist, then check if there is No Refundable.
The below query is not correct but it may give a better idea about what I am trying to achieve:
IF (SELECT ID, Cancellation_Policy_Type, MIN(Cancellation_Policy_Hours) from MYTABLE WHERE Cancellation_Policy_Type = 'Free Cancellation') IS NOT NULL)
THEN (SELECT ID, Cancellation_Policy_Type, MIN(Cancellation_Policy_Hours) from MYTABLE WHERE Cancellation_Policy_Type = 'Free Cancellation')
ELSEIF (SELECT ID, Cancellation_Policy_Type, MIN(Cancellation_Policy_Hours) from MYTABLE WHERE Cancellation_Policy_Type = 'Free Cancellation') IS NULL AND (SELECT ID, Cancellation_Policy_Type, MIN(Cancellation_Policy_Hours from MYTABLE WHERE Cancellation_Policy_Type = 'Partially Refundable') IS NOT NULL Then (SELECT ID, Cancellation_Policy_Type, MIN(Cancellation_Policy_Hours) from MYTABLE WHERE Cancellation_Policy_Type = 'Partially Refundable')
ELSEIF (SELECT ID, Cancellation_Policy_Type, MIN(Cancellation_Policy_Hours) from MYTABLE WHERE Cancellation_Policy_Type = 'Free Cancellation') IS NULL AND (SELECT ID, Cancellation_Policy_Type, MIN(Cancellation_Policy_Hours) from MYTABLE WHERE Cancellation_Policy_Type = 'Partially Refundable') IS NULL THEN (SELECT ID, Cancellation_Policy_Type, MIN(Cancellation_Policy_Hours) from MYTABLE WHERE Cancellation_Policy_Type = 'No Refundable')
END
Below you will find an example of my dataset:
This is the table which contains all data regarding the cancellation policies of every single ID:
ID | Cancellation_Policy_Type | Cancellation_Policy_Hours |
---|---|---|
1 | No Refundable | 17520 |
1 | Partially Refunable | 168 |
1 | Free Cancellation | 96 |
2 | No Refundable | 17520 |
2 | Partially Refunable | 336 |
2 | Free Cancellation | 48 |
3 | No Refundable | 17520 |
3 | Partially Refunable | 336 |
4 | No Refundable | 17520 |
Below is the desired result, that is a table which contains other pieces of information (including production) and the 2 columns where for every single ID repeats the best available cancellation policy type and hours:
ID | Most Flexible Cancellation Type | Most Flexible Cancellation Hours | Other Columns (including buckets) |
---|---|---|---|
1 | Free Cancellation | 96 | a |
1 | Free Cancellation | 96 | b |
1 | Free Cancellation | 96 | c |
2 | Free Cancellation | 48 | a |
2 | Free Cancellation | 48 | b |
2 | Free Cancellation | 48 | c |
3 | Partially Refunable | 336 | a |
3 | Partially Refunable | 336 | b |
3 | Partially Refunable | 336 | c |
4 | No Refundable | 17520 | a |
4 | No Refundable | 17520 | b |
4 | No Refundable | 17520 | c |
SELECT
a.ID
, Most_Flexible_Policy_Type
, Most_Flexible_Cancellation_Hours
, a.BookingWindowBuckets
FROM Production a
LEFT JOIN Property b on a.ID = b.ID
GROUP BY
1,2,3,4
Thank you
2
Answers
You have not given enough information to be able to help you with any degree of confidence that it is the "right" way but (guessing here) you could try –
If you provide an example in the form of full table structure (CREATE statement), some sample data, some stats and the desired outcome you are more likely to get the "right" answer. The above example of conditional aggregation is unlikely to be the best way to do it but it will probably provide what you are looking for. Depending on your dataset, just running the separate queries may be the best solution.
UPDATE
Here is one way of doing this using a window function (MySQL 8) –
I understand that, for each row in
production
, you want to bring from tableproperty
the cancellation policy with the least policy hours.We can do this with window functions to rank the policies of feach
id
, and a join toproduction
: