Oracle SQL: Show entries from component tables once apiece - sql

Question

My objective is produce a dataset that shows a boatload of data from, in total, just shy of 50 tables, all in the same Oracle SQL database schema. Each table except the first consists of, as far as the report I'm building cares, two elements:
A foreign-key identifier that matches a row on the first table
A date
There may be many rows on one of these tables corresponding to one case, and it will NOT be the same number of rows from table to table.
My objective is to have each row in the first table show up as many times as needed to display all the results from the other tables once. So, something like this (except on a lot more tables):
CASE_FILE_ID INITIATED_DATE INSPECTION_DATE PAYMENT_DATE ACTION_DATE
------------ -------------- --------------- ------------ -----------
1000 10-JUL-1986 14-JUL-1987 10-JUL-1986
1000 14-JUL-1988 10-JUL-1987
1000 14-JUL-1989 10-JUL-1988
1000 10-JUL-1989
My current SQL code (shrunk down to five tables, but the rest all follow the same format as T1-T4):
SELECT DISTINCT
A.CASE_FILE_ID,
T1.DATE AS INITIATED_DATE,
T2.DATE AS INSPECTION_DATE,
T3.DATE AS PAYMENT_DATE,
T4.DATE AS ACTION_DATE
FROM
RECORDS.CASE_FILE A
LEFT OUTER JOIN RECORDS.INITIATE T1 ON A.CASE_FILE_ID = T1.CASE_FILE_ID
LEFT OUTER JOIN RECORDS.INSPECTION T2 ON A.CASE_FILE_ID = T2.CASE_FILE_ID
LEFT OUTER JOIN RECORDS.PAYMENT T3 ON A.CASE_FILE_ID = T3.CASE_FILE_ID
LEFT OUTER JOIN RECORDS.ACTION T4 ON A.CASE_FILE_ID = T4.CASE_FILE_ID
ORDER BY
A.CASE_FILE_ID
The problem is, the output this produces results in distinct combinations; so in the above example (where I added a 'WHERE' clause of A.CASE_FILE_ID = '1000'), instead of four rows for case 1000, it'd show twelve (1 Initiated Date * 3 Inspection Dates * 4 Payment Dates = 12 rows). Suffice it to say, as the number of tables increases, this would get very prohibitive in both display and runtime, very quickly.
What is the best way to get an output loosely akin to the ideal above, where any one date is only shown once? Failing that, is there a way to get it to only show as many lines for one CASE_FILE as it needs to show all the dates, even if some dates repeat within that?

Answer 1

There isn't a good way, but there are two ways. One method involves subqueries for each table and complex outer joins. The second involves subqueries and union all. Let's go with that one:
SELECT CASE_FILE_ID,
MAX(INITIATED_DATE) as INITIATED_DATE,
MAX(INSPECTION_DATE) as INSPECTION_DATE,
MAX(PAYMENT_DATE) as PAYMENT_DATE,
MAX(ACTION) as ACTION
FROM ((SELECT A.CASE_FILE_ID, NULL as INITIATED_DATE, NULL as INSPECTION_DATE,
NULL as PAYMENT_DATE, NULL as ACTION_DATE,
1 as seqnum
FROM RECORDS.CASE_FILE A
) UNION ALL
(SELECT T1.CASE_FILE_ID, DATE as INITIATED_DATE, NULL as INSPECTION_DATE,
NULL as PAYMENT_DATE, NULL as ACTION_DATE,
ROW_NUMBER() OVER (PARTITION BY CASE_FILE_ID ORDER BY DATE) as seqnum
FROM RECORDS.INITIATE
) UNION ALL
(SELECT T1.CASE_FILE_ID, NULL as INITIATED_DATE, DATE as INSPECTION_DATE,
NULL as PAYMENT_DATE, NULL as ACTION_DATE,
ROW_NUMBER() OVER (PARTITION BY CASE_FILE_ID ORDER BY DATE) as seqnum
FROM RECORDS.INSPECTION
) UNION ALL
(SELECT T1.CASE_FILE_ID, NULL as INITIATED_DATE, NULL as INSPECTION_DATE,
DATE as PAYMENT_DATE, NULL as ACTION_DATE,
ROW_NUMBER() OVER (PARTITION BY CASE_FILE_ID ORDER BY DATE) as seqnum
FROM RECORDS.PAYMENT
) UNION ALL
(SELECT T1.CASE_FILE_ID, NULL as INITIATED_DATE, NULL as INSPECTION_DATE,
NULL as PAYMENT_DATE, ACTION as ACTION_DATE,
ROW_NUMBER() OVER (PARTITION BY CASE_FILE_ID ORDER BY DATE) as seqnum
FROM RECORDS.ACTION
)
) a
GROUP BY CASE_FILE_ID, seqnum;
Hmmm, a closely related solution is easier to maintain:
SELECT CASE_FILE_ID,
MAX(CASE WHEN type = 'INITIATED' THEN DATE END) as INITIATED_DATE,
MAX(CASE WHEN type = 'INSPECTION' THEN DATE END) as INSPECTION_DATE,
MAX(CASE WHEN type = 'PAYMENT' THEN DATE END) as PAYMENT_DATE,
MAX(CASE WHEN type = 'ACTION' THEN DATE END) as ACTION
FROM ((SELECT A.CASE_FILE_ID, NULL as TYPE, NULL as DATE,
1 as seqnum
FROM RECORDS.CASE_FILE A
) UNION ALL
(SELECT T1.CASE_FILE_ID, 'INSPECTION', DATE,
ROW_NUMBER() OVER (PARTITION BY CASE_FILE_ID ORDER BY DATE) as seqnum
FROM RECORDS.INITIATE
) UNION ALL
(SELECT T1.CASE_FILE_ID, 'INSPECTION', DATE,
ROW_NUMBER() OVER (PARTITION BY CASE_FILE_ID ORDER BY DATE) as seqnum
FROM RECORDS.INSPECTION
) UNION ALL
(SELECT T1.CASE_FILE_ID, 'PAYMENT', DATE,
ROW_NUMBER() OVER (PARTITION BY CASE_FILE_ID ORDER BY DATE) as seqnum
FROM RECORDS.PAYMENT
) UNION ALL
(SELECT T1.CASE_FILE_ID, 'ACTION', DATE,
ROW_NUMBER() OVER (PARTITION BY CASE_FILE_ID ORDER BY DATE) as seqnum
FROM RECORDS.ACTION
)
) a
GROUP BY CASE_FILE_ID, seqnum;