Create a SQL column based on list of values - sql

Question

I am trying to create a column dependent on whether a certain value exists in a list regardless of when it occurs.
In my table currently I have:
Attendee No - unique number for every attendance Tracking Activity -
Description of Activity Tracking Date/Time - Date & Time when
Activity took place Activity Type - <<<< I need to calculate this
column based on specific logic
[Attendee No] can have multiple [Tracking Activity] & associated [Tracking Date/Time]
Table example. Tracker
+-------------+-------------------+--------------------+---------------+
| Attendee_No | Tracking Activity | Tracking Date/Time | Activity Type |
+-------------+-------------------+--------------------+---------------+
| 3623 | Eat | 05/04/2020 16:28 | Physical |
| 3623 | Music | 05/04/2020 07:16 | Physical |
| 3623 | Run | 05/04/2020 03:52 | Physical |
| 3623 | Booked in | 05/04/2020 03:42 | Physical |
| 3624 | Sleep | 05/04/2020 15:47 | Physical |
| 3624 | Walk | 05/04/2020 11:55 | Physical |
| 3624 | TV | 05/04/2020 11:54 | Physical |
| 3624 | Booked in | 05/04/2020 11:52 | Physical |
+-------------+------------------+--------------------+----------------+
Using the example above what im looking to do is:
For every Attendee No if the Tracker Activity = "Run", "Walk", "Jog", "Gym" regardless when it occurred the Activity Type should = "Physical"
im a SQL noob so have no idea what im doing really so your help will be SOOOO GRATEFULLY appreciated!

Answer 1

For every Attendee No if the Tracker Activity = "Run", "Walk", "Jog", "Gym" regardless when it occurred the Activity Type should = "Physical"
SELECT
CASE
WHEN activity IN('Run','Walk','Jog','Gym') THEN 'Physical'
--WHEN .... other boolean test .. THEN ... other output value...
--ELSE .. catch all value...
END as ActivityType
FROM
...
The -- is commented out - i put these things in as comments to show you how to add more cases, and how to add an else. If you want to use them, uncomment them and modify them.
CASE WHEN has to perform X number of tests and return a single value. It cannot return multiple values
CASE WHEN can also be written like:
CASE activity
WHEN 'Walk' THEN 'Physical'
WHEN 'Jog' THEN 'Physical'
...
--ELSE ...
In this format, you can only supply a single value after the WHEN, and it is compared using =. You can't CASE column WHEN > 0 THEN.. or CASE column WHEN value AND othercolumn = blah THEN..
If you want those kinds of complexity you have to use the CASE WHEN column > 0 AND othercolumn = blah THEN.. form
If you get lots of variations, or you expect to be able to add more in the future without modifying the sql, create another table that has two columns:
Activity,ActivityType
------------
Run,Physical
Walk,Physical
Jog,Physical
Gym,Physical
Study,Mental
...
And join it in:
SELECT * FROM
table t
INNER JOIN activityTypes a ON a.Activity = t.Activity

Answer 2

YOu can have a CASE logic to calculate the Activity Type.
As a general best practice, when you are naming the columns, avoid
below things. They will lead to issues one or other way.
Names with spaces
Keywords
Names with -
types names
SELECT [Attendee No], [Tracking Activity],[Tracking Date/Time],
CASE WHEN [Tracking Activity] IN ( 'Run', 'Walk', 'Jog', 'Gym') THEN 'Physical'
ELSE 'NOT Physical' END AS [Activity Type]
FROM Tracker

Answer 3

I started off with the case statement but what im getting blanks when the Tracking Activity is not in the list. I need ALL the activity type to say "Physical" if the attendee has 'Run', 'Walk', 'Jog', 'Gym' at anytime in the Attendee_No

Answer 4

You can use SQL CASE syntax to achieve it.
See SQL CASE on W3SCHOOLS
Modify your SQL to something like the following and it should do the trick.
SQL
SELECT Attendance_No, Tracking_date,
CASE
WHEN Tracking_activity = 'Run' THEN 'Physical'
WHEN Tracking_ctivity = 'Walk' THEN 'Physical'
WHEN Tracking_ctivity = 'Jog' THEN 'Physical'
WHEN Tracking_ctivity = 'Gym' THEN 'Physical'
ELSE `Other`
END AS 'Activity-type'
FROM Tracker