ORACLE SQL - SELECT SUM from One Table With Conditions in Another Table

Question

I have two tables: SZRATND and SFRSTCR.

+--------------+-------------------+-------------+-------------------+-----------------------+---------------------+
| SZRATND_PIDM | SZRATND_TERM_CODE | SZRATND_CRN | SZRATND_RSTS_CODE | SZRATND_ATTENDING_IND | SZRATND_LAST_ATTEND |
+--------------+-------------------+-------------+-------------------+-----------------------+---------------------+
|       264185 |            201480 |       82223 | RE                | Y                     |                     |
|       264185 |            201710 |       10716 | RW                | N                     | 1/16/2017           |
|       264185 |            201710 |       10943 | RW                | S                     | 4/29/2017           |
|       264185 |            201710 |       10960 | RW                | S                     | 4/29/2017           |
|       264185 |            201710 |       11362 | RW                | S                     | 4/10/2017           |
|       264185 |            201580 |       80094 | RE                | Y                     |                     |
|       264185 |            201610 |       10439 | D2                | Y                     |                     |
|       264185 |            201680 |       80769 | RW                | Y                     |                     |
|       264185 |            201680 |       82184 | RW                | Y                     |                     |
|       264185 |            201680 |       82114 | RW                | Y                     |                     |
|       264185 |            201680 |       80806 | RW                | Y                     |                     |
+--------------+-------------------+-------------+-------------------+-----------------------+---------------------+



+--------------+-------------------+-------------+-------------------+-------------------+
| SFRSTCR_PIDM | SFRSTCR_TERM_CODE | SFRSTCR_CRN | SFRSTCR_RSTS_CODE | SFRSTCR_CREDIT_HR |
+--------------+-------------------+-------------+-------------------+-------------------+
|       264185 |            201480 |       82223 | RE                |                 1 |
|       264185 |            201580 |       80094 | RE                |                 1 |
|       264185 |            201610 |       10439 | D2                |                 0 |
|       264185 |            201680 |       80769 | RW                |                 3 |
|       264185 |            201680 |       80806 | RW                |                 3 |
|       264185 |            201680 |       82114 | RW                |                 3 |
|       264185 |            201680 |       82184 | RW                |                 3 |
|       264185 |            201710 |       10716 | RW                |                 3 |
|       264185 |            201710 |       10943 | RW                |                 3 |
|       264185 |            201710 |       10960 | RW                |                 3 |
|       264185 |            201710 |       11362 | RW                |                 3 |
+--------------+-------------------+-------------+-------------------+-------------------+

The data shown is for one PIDM (person).
I need the SUM of SFRSTCR_CREDIT_HR for the rows where SZRATND_ATTENDING_IND = 'Y'
The PIDM, TERM_CODE, CRN, and RSTS_CODEs for both tables must match.

My desired and actual results FOR SZRATND_ATTENDING_IND = 'Y'

+--------------+-------------------+----+-----------------+
|              | DESIRED RESULT    |    | ACTUAL RESULT   |  
+--------------+-------------------+----+-----------------+   
| SFRSTCR_PIDM | ATTENDING_HOURS   |    | ATTENDING_HOURS | 
| 264185       | 0                 |    | 14              |
+--------------+-------------------+----+-----------------+   

Code:

SELECT DISTINCT  
F.SFRSTCR_PIDM,
REG.STUDENT_REG_HRS AS STUDENT_REG_HRS,
ATTENDING.ATT_HRS AS STUDENT_ATT_HRS

FROM SFRSTCR F 
JOIN (SELECT SFRSTCR_PIDM, SUM(SFRSTCR_CREDIT_HR) AS ATT_HRS
                    FROM SZRATND ATTEND 
                    JOIN SFRSTCR  ON SFRSTCR_PIDM = ATTEND.SZRATND_PIDM
                    WHERE ATTEND.SZRATND_TERM_CODE = SFRSTCR_TERM_CODE
                      AND ATTEND.SZRATND_RSTS_CODE = SFRSTCR_RSTS_CODE
                      AND ATTEND.SZRATND_CRN = SFRSTCR_CRN
                      AND ATTEND.SZRATND_ATTENDING_IND = 'Y'
                    GROUP BY SFRSTCR_PIDM) ATTENDING ON F.SFRSTCR_PIDM = ATTENDING.SFRSTCR_PIDM

JOIN (SELECT SF.SFRSTCR_PIDM, SUM(SF.SFRSTCR_CREDIT_HR) AS STUDENT_REG_HRS
FROM SFRSTCR SF 
WHERE SF.SFRSTCR_RSTS_CODE LIKE 'R%'
AND SF.SFRSTCR_TERM_CODE = '201710'
GROUP BY SF.SFRSTCR_PIDM)REG ON F.SFRSTCR_PIDM = REG.SFRSTCR_PIDM 

WHERE 
F.SFRSTCR_RSTS_CODE LIKE 'R%'
AND F.SFRSTCR_TERM_CODE = '201710'
AND F.SFRSTCR_PIDM ='264185'

I have tried several things, but nothing seems to give me the correct results.

This code works to pull the number of hours a student is attending, but when I add the GROUP BY clause, it makes the result incorrect. This is the code that should be in the "ATTENDING join." Any ideas how I can include this?

SELECT NVL(SUM(SFRSTCR_CREDIT_HR), 0) AS ATT_HRS
    FROM SFRSTCR 
    JOIN SZRATND ATTEND  ON SFRSTCR_PIDM = ATTEND.SZRATND_PIDM
               AND ATTEND.SZRATND_TERM_CODE = SFRSTCR_TERM_CODE
               AND ATTEND.SZRATND_ATTENDING_IND = 'Y'
               AND ATTEND.SZRATND_RSTS_CODE = SFRSTCR_RSTS_CODE
               AND ATTEND.SZRATND_CRN = SFRSTCR_CRN

    WHERE SFRSTCR_PIDM ='264185'
    AND SFRSTCR_TERM_CODE = '201710'
    AND SFRSTCR_RSTS_CODE LIKE 'R%'  

FINAL CORRECTED CODE:

SELECT DISTINCT
SPRIDEN_ID AS "ID",
SPRIDEN_LAST_NAME AS "LAST_NAME",
SPRIDEN_FIRST_NAME AS "FIRST_NAME",
ROBUSDF_VALUE_24 AS "FallTNP_Eligibility",
ROBUSDF_VALUE_25 AS "SpringTNP_Eligibility",
ROBUSDF_VALUE_26 AS "SummerTNP_Eligibility",
F.SFRSTCR_TERM_CODE AS "ENROLLED_TERM",
REG.STUDENT_REG_HRS AS STUDENT_REG_HRS,
ATT.ATT_HRS AS STUDENT_ATT_HRS

--CASE WHEN REG.STUDENT_REG_HRS <> ATT.ATT_HRS THEN 'LOOK' END AS "LOOK"

FROM SFRSTCR F
JOIN SPRIDEN ON F.SFRSTCR_PIDM = SPRIDEN_PIDM
LEFT OUTER JOIN ROBUSDF ON SPRIDEN_PIDM = ROBUSDF_PIDM
                    AND ROBUSDF_VALUE_36 = 'Y'
                    AND ROBUSDF_AIDY_CODE = :AidYear.AidYear
LEFT JOIN( SELECT NVL( SUM(SFRSTCR_CREDIT_HR), 0) AS ATT_HRS, SFRSTCR_PIDM AS ATT_PIDM
    FROM SFRSTCR
    JOIN SZRATND ATTEND  ON SFRSTCR_PIDM = ATTEND.SZRATND_PIDM
           AND ATTEND.SZRATND_TERM_CODE = SFRSTCR_TERM_CODE
           AND ATTEND.SZRATND_ATTENDING_IND = 'Y'
           AND ATTEND.SZRATND_RSTS_CODE = SFRSTCR_RSTS_CODE
           AND ATTEND.SZRATND_CRN = SFRSTCR_CRN
    WHERE
    SFRSTCR_TERM_CODE IN (:Term.TermCode,:Term.TermCode + 9)
    AND SFRSTCR_RSTS_CODE LIKE 'R%'
    GROUP BY SFRSTCR_PIDM
    ) ATT ON F.SFRSTCR_PIDM = ATT.ATT_PIDM

JOIN (SELECT SF.SFRSTCR_PIDM, SUM(SF.SFRSTCR_CREDIT_HR) AS STUDENT_REG_HRS
    FROM SFRSTCR SF
    WHERE SF.SFRSTCR_RSTS_CODE LIKE 'R%'
    AND SF.SFRSTCR_TERM_CODE IN (:Term.TermCode,:Term.TermCode + 9)
    GROUP BY SF.SFRSTCR_PIDM)REG ON F.SFRSTCR_PIDM = REG.SFRSTCR_PIDM

WHERE
SPRIDEN_CHANGE_IND IS NULL
AND F.SFRSTCR_RSTS_CODE LIKE 'R%'
AND F.SFRSTCR_TERM_CODE IN (:Term.TermCode,:Term.TermCode + 9)
AND ROBUSDF_VALUE_36 = 'Y'
ORDER BY SPRIDEN_ID  

Thorsten Kettner, you are the best! Thank you for your patience!

Answer 1

I must admit I haven't looked much at your query. It looks so complicated while it seems you simply want to join the tables and then get the credit_hr sum per attending_ind. That would be:

select
  z.szratnd_attending_ind,
  sum(f.sfrstcr_credit_hr) as attending_hrs
from szratnd z
join sfrstcr f on  f.szratnd_pidm      = z.szratnd_pidm
               and f.szratnd_term_code = z.szratnd_term_code
               and f.szratnd_crn       = z.szratnd_crn
               and f.szratnd_rsts_code = z.szratnd_rsts_code
where z.szratnd_pidm = 264185
group by szratnd_attending_ind;

As to your modified query:

1. It seems you have forgotton SZRATND_CRN in your ON clause.
2. You outer join SZRATND , but you don't use it anywhere in your query. You can just as well remove this completely.
3. You inner join the total SFRSTCR_CREDIT_HR per student and :REG_TERM . This can be different from '201710' you are using in your main query. So if there is no match for :REG_TERM , you dismiss the student's records.
4. You are grouping by SFRSTCR_CREDIT_HR . I don't know why. This gives you two sums, one for 264185|1 , one for 264185|3 . And you don't even show for which group you are displaying the sum ( SFRSTCR_CREDIT_HR is not in your select list).
5. DISTINCT is very often a sign for a badly written query. The one thing it does here is this: If you find, say, six records for 264185|1 and two records for 264185|3 , then you'd get 264185|6 and 264185|6 (because 1 x 6 = 6 and 2 x 3 = 6). In such a case you'd dismiss one of the rows as a duplicate. Doesn't seem to make sense to me.