left join tables with multiple conditions

Question

I'm struggling with one query. I need to LEFT JOIN two tables where the specific id match and where dates differ:

SELECT
    *
FROM
    u_data ud
JOIN
    u_contracts uc
ON
    uc.user_id = ud.id
LEFT JOIN
    u_transactions ut
ON
    ut.contract_id = uc.id
    /* AND DATE( ut.add_timestamp ) > DATE( ud.suspicious ) */
WHERE
    ud.suspicious > 0
    AND ud.suspicious != ''
    AND ud.suspicious IS NOT NULL
    AND uc._status = 6
GROUP BY
    ud.id;

This gives my the right count of rows, but I also need to check, if the transaction date is greater then suspicious date from the first table. As soon as I add that condition ( tried in where at start too ), it eliminates all fields, where there is no transaction date.

Meaning, if I LEFT JOIN those tables, I get a result like this:

+-----+----------+---------------+---------------+--------+
| row | original | ud.suspicious | add_timestamp | amount |
+-----+----------+---------------+---------------+--------+
|   1 |      100 | 10.01.2000    | 01.01.2000    |     50 |
|   2 |      100 | 10.01.2000    | NULL          | NULL   |
|   3 |      100 | 10.01.2000    | 12.01.2000    |     10 |
|   4 |      100 | 11.01.2000    | 12.01.2000    |     20 |
|   5 |      100 | 12.01.2000    | 12.01.2000    |     30 |
+-----+----------+---------------+---------------+--------+

Now, I basically need to eliminate the amount and date for 01.01.2000, since it is older then suspicious date and I don't need the additional amount, but I need the original though. This is what I need to get

+-----+----------+---------------+---------------+--------+
| row | original | ud.suspicious | add_timestamp | amount |
+-----+----------+---------------+---------------+--------+
|   1 |      100 | 10.01.2000    | NULL          | NULL   |
|   2 |      100 | 10.01.2000    | NULL          | NULL   |
|   3 |      100 | 10.01.2000    | 12.01.2000    |     10 |
|   4 |      100 | 11.01.2000    | 12.01.2000    |     20 |
|   5 |      100 | 12.01.2000    | 12.01.2000    |     30 |
+-----+----------+---------------+---------------+--------+

But when I set that condition DATE( ut.add_timestamp ) > DATE( ud.suspicious ) I get this:

+-----+----------+---------------+---------------+--------+
| row | original | ud.suspicious | add_timestamp | amount |
+-----+----------+---------------+---------------+--------+
|   1 |      100 | 10.01.2000    | 12.01.2000    |     10 |
|   2 |      100 | 11.01.2000    | 12.01.2000    |     20 |
|   3 |      100 | 12.01.2000    | 12.01.2000    |     30 |
+-----+----------+---------------+---------------+--------+

Why is it removing the entries with LEFT JOIN and how can I fix this to get the right data I need?

---

Edit: The full original working query:

SELECT
    ud.Pcode AS pcode
    , CONCAT( ud.Name, ' ', ud.Surname ) AS name
    , CONCAT(
        ud.Da_CityName,
        IF ( ud.Da_Street != '', CONCAT( ', ', ud.Da_Street ), '' ),
        IF ( ud.Da_Housen != '', CONCAT( ', ', ud.Da_Housen ), '' ),
        IF ( ud.Da_Flatn != '', CONCAT( ', ', ud.Da_Flatn ), '' ),
        IF ( ud.Da_PostIndex != '', CONCAT( ', ', ud.Da_PostIndex ), '' )
    ) AS address
    , uc.id AS contract_id
    , uc.terminate_date AS terminate_date
    , FORMAT( IF ( (
        SELECT
            SUM( external_account )
        FROM
            u_transactions
        WHERE
            contract_id = uc.id 
            AND nulled = 0
            AND type in ( 'penalty', 'initial', 'comission', 'penalty2', 'penalty2_vat' )
            AND DATE( add_timestamp ) > DATE( ud.suspicious )
    ) IS NULL, uc.inkasso_debt, uc.inkasso_debt - (
        SELECT
            SUM( external_account )
        FROM
            u_transactions
        WHERE
            contract_id = uc.id 
            AND nulled = 0
            AND type in ( 'penalty', 'initial', 'comission', 'penalty2', 'penalty2_vat' )
            AND DATE( add_timestamp ) > DATE( ud.suspicious )
    ) ), 2 ) AS summ
FROM
    u_data ud
JOIN
    u_contracts uc
ON
    uc.user_id = ud.id
WHERE
    ud.suspicious > 0
    AND ud.suspicious != ''
    AND ud.suspicious IS NOT NULL
    AND uc._status = 6
    AND DATE( uc.terminate_date ) < ( NOW() - INTERVAL 45 DAY )

As it is too messy, I'm trying to get rid of the two subselects and join them to get the SUM( external_account ) amount. Maybe this will help to understand my issue.

Answer 1

Try

...
RIGHT JOIN u_transactions ut
ON ut.contract_id = uc.id
AND ( DATE( ut.add_timestamp ) > DATE( ud.suspicious )
      OR ut.add_timestamp IS NULL )
...

in your query