sqllite query to count across rows - sqlite

Question

I create an audit trail to record every change in one of my project databases.
I have a table called DatabaseAudit with the columns and some sample values below. Type can be "Insert", "Update", or "Delete"
Id, Timestamp, Type, RecordId
1, 637052212796419902, Update, 13
2, 637052213295073040, Update, 15
3, 637052213388962058, Update, 22
4, 637052213494632806, Update, 3
5, 637052213604466165, Update, 25
When Type = "Insert" or "Update", I record the actual values in a table called TableAudit with the columns below
DatabaseAuditId, ColumnName, PreviousValue, NewValue
1, Col1, False, True
1, Col2, , P
2, Col1, False, True
2, Col2, , P
3, Col1, False, True
3, Col2, , M
4, Col1, True, False
4, Col2, , P
5, Col1, False, True
5, Col2, , M
I am having a hard time generating a query. For example, I'd like the count of the number of DatabaseAudit entries where the Col1 new value is "True" and Col2 new value is "P". Which for this example would be 2.

Answer 1

Try this one:
WITH q1 AS (SELECT DISTINCT Count(*) FROM TableAudit WHERE
(ColumnName = 'Col1' AND NewValue = 'True') OR
(ColumnName = 'Col2' AND NewValue = 'P')
Group by DatabaseAuditId
)
SELECT count(*) FROM q1
Hope it helps.

Answer 2

SELECT count(*) AS MatchCount
FROM (SELECT id
FROM DatabaseAudit AS d
JOIN TableAudit AS t ON d.Id = t.DatabaseAuditId
WHERE (t.ColumnName, t.NewValue) = ('Col1', 'True')
OR (t.columnName, t.NewValue) = ('Col2', 'P')
GROUP BY d.Id
HAVING count(*) = 2);
MatchCount
----------
2

Answer 3

For each DatabaseAuditId with ColumnName = 'Col1' and NewValue = 'True' check if there is a row with the same DatabaseAuditId and ColumnName = 'Col2' and NewValue = 'P' with EXISTS:
select count(*) counter
from TableAudit t
where t.ColumnName = 'Col1' and t.NewValue = 'True'
and exists (
select 1 from TableAudit
where DatabaseAuditId = t.DatabaseAuditId and ColumnName = 'Col2' and NewValue = 'P'
)
See the demo.
Results:
| counter |
| ------- |
| 2 |