SQL to return 1 or 0 depending on values in a column's audit trail - sql

Question

If I were to have a table such as the one below:
id_
last_updated_by
1
robot
1
human
1
robot
2
robot
3
robot
3
human
Using SQL, how could I group by the ID and create a new column to indicate whether a human has ever updated the record like this:
id_
last_updated_by
updated_by_human
1
robot
1
2
robot
0
3
robot
1
UPDATE
I'm currently doing the following, though I'm not sure how efficient this is. Selecting the latest record and then merging it with my calculated column via a sub-select.
SELECT MAIN.TRANSACTION_ID,
MAIN.CREATED_DATE
MAIN.CREATED_BY_USER_ID,
MAIN.OWNER_USER_ID,
STP.TOUCHED_BY_HUMAN
FROM (
SELECT TRANSACTION_ID,
CREATED_DATE
CREATED_BY_USER_ID_
OWNER_USER_ID_
FROM TABLE_NAME
WHERE CREATED_DATE >= CAST('{start_date} 00:00:00' AS TIMESTAMP)
AND CREATED_DATE <= CAST('{end_date} 23:59:59' AS TIMESTAMP)
QUALIFY row_number() OVER (partition by TRANSACTION_ID order by End_Dt desc) = 1
) MAIN
LEFT JOIN (
SELECT TRANSACTION_ID,
CASE
WHEN CREATED_BY_USER_ID IN ('ROBOT', 'MACHINE') OR
CREATED_BY_USER_ID LIKE 'N%' OR
CREATED_BY_USER_ID IS NULL
THEN 0
ELSE 1 END AS CREATED_BY_HUMAN,
CASE
WHEN OWNER_USER_ID IN ('ROBOT', 'MACHINE') OR
OWNER_USER_ID LIKE 'N%' OR
OWNER_USER_ID IS NULL
THEN 0
ELSE 1 END AS OWNED_BY_HUMAN,
CASE
WHEN CREATED_BY_HUMAN = 0 AND
OWNED_BY_HUMAN = 0
THEN 0
ELSE 1 END AS TOUCHED_BY_HUMAN_
FROM TABLE_NAME
WHERE CREATED_DATE >= CAST('{start_date} 00:00:00' AS TIMESTAMP)
AND CREATED_DATE <= CAST('{end_date} 23:59:59' AS TIMESTAMP)
QUALIFY row_number() OVER (partition by TRANSACTION_ID order by TOUCHED_BY_HUMAN_ desc) = 1
) STP
ON MAIN.TRANSACTION_ID = STP.TRANSACTION_ID

Answer 1

If I'm following your problem, then something like this should work.
SELECT
t.*
,CASE WHEN a.id IS NOT NULL THEN 1 ELSE 0 END AS updated_by_human
FROM table t
LEFT JOIN (SELECT DISTINCT id FROM table WHERE last_updated_by = 'human') a ON t.id = a.id
That takes care of the updated_by_human field, but if you also need to reduce the records in table (only keeping a subset) then you need more information to do that.

Answer 2

Exists clauses are usually not that performant but if your data isn't big this should work.
select id_,
IF (EXISTS (SELECT 1 FROM table_name t2 WHERE t2.last_updated_by = 'human' and t2.id_ = t1.id_), 1, 0) AS updated_by_human
from table_name t1;
here is another way
SELECT *
FROM table_name t1
GROUP BY ti.id_
HAVING COUNT(*) > 0
AND MAX(CASE t1.last_updated_by WHEN 'human' THEN 1 ELSE 0 END) = 1;

Answer 3

Since you didn't specified which column is used to determine this record is the newest record added by a given id, I assume that there will be a column to track the insert/modify timestamp (which is pretty standard table design), let's put it is last_updated_timestamp (if you don't have any, then I still insist you to have one as an auditing trail without timestamp does not make sense)
Given your table name is updating_trail
SELECT updating_trail.*, last_update_trail.modified_by_human
FROM updating_trail
INNER JOIN (
-- determine the id_, the lastest modified_timestamp, and a flag check to determine if there is any record with last_update_by is 'human' -> if yes then give 1
SELECT updating_trail.id_, MAX(last_update_timestamp) AS most_recent_update_ts, MAX(CASE WHEN updating_trail.last_updated_by = 'human' THEN 1 ELSE 0 END) AS modified_by_human
FROM updating_trail
GROUP BY updating_trail.id_
) last_update_trail
ON updating_trail.id_ = last_update_trail.id_ AND updating_trail.last_update_timestamp = last_update_trail.most_recent_update_ts;
Give
id_
last_updated_by
last_update_timestamp
modified_by_human
1
robot
2021-10-19T20:00:00.000Z
1
2
robot
2021-10-19T17:00:00.000Z
0
3
robot
2021-10-19T16:00:00.000Z
1
Check out this sample db fiddle I created for you

Answer 4

This is a 1:1 translation of your query to conditional aggregation:
SELECT TRANSACTION_ID,
CREATED_DATE,
CREATED_BY_USER_ID,
OWNER_USER_ID,
Max(CASE
WHEN CREATED_BY_USER_ID IN ('ROBOT', 'MACHINE') OR
CREATED_BY_USER_ID LIKE 'N%' OR
CREATED_BY_USER_ID IS NULL
THEN 0
ELSE 1
END) Over (PARTITION BY TRANSACTION_ID) AS CREATED_BY_HUMAN
FROM Table_Name
WHERE CREATED_DATE >= Cast('{start_date} 00:00:00' AS TIMESTAMP)
AND CREATED_DATE <= Cast('{end_date} 23:59:59' AS TIMESTAMP)
QUALIFY Row_Number() Over (PARTITION BY TRANSACTION_ID ORDER BY End_Dt DESC) = 1