JOIN TABLE IN ORACLE

问题

I have a table with 100000 records and I get 97000 records as part of this below query how to get the remaining 30000 records. I tried not equal to 'H.RESOURCE_ID <> SQ.CPNT_OG_ID' but not getting correct data?

SELECT H.pernr AS "STUD_ID",
       SQ.CPNT_TYP_ID,
       SQ.CPNT_ID,
       TO_CHAR (SQ.REV_DTE, 'MON-DD-YYYY HH24:MI:SS') AS REV_DTE,
       CASE                                                           --WAIVED
          WHEN sq.CPNT_TYP_ID = 'VIDEO' AND enrollment_status = 'Complete'
          THEN
             'VIDEO-COMPLETE'
          WHEN sq.CPNT_TYP_ID = 'VIDEO' AND enrollment_status <> 'Complete'
          THEN
             'VIDEO-WAIVED'
          WHEN     sq.CPNT_TYP_ID = 'CERTIFICATION'
               AND enrollment_status = 'Complete'
          THEN
             'CERT-COMPLETE'
          WHEN     sq.CPNT_TYP_ID = 'CERTIFICATION'
               AND enrollment_status <> 'Complete'
          THEN
             'CERT-WAIVED'
          WHEN sq.CPNT_TYP_ID = 'CDOC' AND enrollment_status = 'Complete'
          THEN
             'CDOC-COMPLETE'
          WHEN sq.CPNT_TYP_ID = 'CDOC' AND enrollment_status <> 'Complete'
          THEN
             'CDOC-WAIVED'
          WHEN     sq.CPNT_TYP_ID = 'ELEARNING'
               AND enrollment_status = 'Complete'
          THEN
             'Elearning-COMPLETE-PASSED'
          WHEN     sq.CPNT_TYP_ID = 'ELEARNING'
               AND enrollment_status <> 'Complete'
          THEN
             'Elearning-WAIVED'
          ELSE
             NULL
       END
          "CMPL_STAT_ID",
       TO_CHAR (H.COMPLETION_DATE, 'MON-DD-YYYY HH24:MI:SS')
          AS COMPLETION_DATE,
       'RECORD_Admin'
          AS "ESIG_MEANING_CODE_ID",
       NULL                                           AS "LST_UPD_USR",
       sq.rev_num                                     AS "REV_NUM",
       'LEARNSHARE'                                   AS "COMMENTS"
  FROM ZB_USR_HISTORY_NEW H
       JOIN
       (SELECT DISTINCT CPNT_ID,
                        CPNT_TYP_ID,
                        CPNT_OG_ID,
                        REV_DTE,
                        REV_NUM,
                        CPNT_COURSE_NUM
          FROM TBL_ZIM_ITEM_new
         WHERE VALID = '1' AND app_id LIKE '%en-us%' OR LENGTH (app_id) < 9)
       SQ
          ON (H.RESOURCE_ID = SQ.CPNT_OG_ID);

回答1:

Just replace JOIN with LEFT JOIN. You can use LEFT JOIN or RIGHT JOIN in SQL in order to also fetch the record that do not satisfy the join condition. The columns selected in the non-existing row will be NULL.

来源：https://stackoverflow.com/questions/42805398/join-table-in-oracle