Restructure the SQL query

Question

When i run the below query i get the following error.
ORA - 00904: t.associate_id : invalid identifier.
SELECT t.product_id,
       t.associate_id,
       pd.status,
       CASE
            WHEN pd.status NOT IN ('DEAD', 'COMPLETED') THEN
             fn_get_user_type(t.associate_id, SYSDATE)
            WHEN pd.status = 'COMPLETED' THEN
             fn_get_user_type(t.associate_id, pd.actual_completion_date)
            WHEN pd.status = ('DEAD') THEN
             fn_get_user_type(t.associate_id, pd.est_completion_date)
       END
  FROM team t,
       product pd,
       (SELECT *
          FROM (SELECT *
                  FROM associate_org
                 WHERE associate_id = t.associate_id     -------    getting error in this line
                       AND SYSDATE BETWEEN start_date AND end_date
                 ORDER BY end_date DESC)
         WHERE rownum < 2) ao
WHERE pd.product_id = t.product_id
       AND ao.associate_id = t.associate_id
       AND t.end_date IS NULL
How to restructure the query to avoid this error?
Thanks

Answer 1

You can't correlate FROM list items. Anyway, since select list has no references to in-line view ao:
SELECT t.product_id,
       t.associate_id,
       pd.status,
       CASE
            WHEN pd.status NOT IN ('DEAD', 'COMPLETED') THEN
             fn_get_user_type(t.associate_id, SYSDATE)
            WHEN pd.status = 'COMPLETED' THEN
             fn_get_user_type(t.associate_id, pd.actual_completion_date)
            WHEN pd.status = ('DEAD') THEN
             fn_get_user_type(t.associate_id, pd.est_completion_date)
       END
  FROM team t,
       product pd
WHERE pd.product_id = t.product_id
       AND EXISTS (
                   SELECT  1
                     FROM  associate_org ao
                     WHERE SYSDATE BETWEEN start_date AND end_date
                       AND ao.associate_id = t.associate_id
       AND t.end_date IS NULL
If you provided just a snippet of real query and real select list has references to ao:
SELECT t.product_id,
       t.associate_id,
       pd.status,
       CASE
            WHEN pd.status NOT IN ('DEAD', 'COMPLETED') THEN
             fn_get_user_type(t.associate_id, SYSDATE)
            WHEN pd.status = 'COMPLETED' THEN
             fn_get_user_type(t.associate_id, pd.actual_completion_date)
            WHEN pd.status = ('DEAD') THEN
             fn_get_user_type(t.associate_id, pd.est_completion_date)
       END
  FROM team t,
       product pd,
       (SELECT ao.*,
               row_number() over(partition by associate_id order by end_date desc) rn
          FROM associate_org ao
          WHERE SYSDATE BETWEEN start_date AND end_date
       ) ao
WHERE pd.product_id = t.product_id
       AND ao.associate_id = t.associate_id
       AND ao.rn = 1
       AND t.end_date IS NULLSY.