Distinct select on Oracle
- by funktku
What i am trying to do is a simple recommender , must take the biggest weighted top 40 element's node2 element. Calculation for weight comes from (E.WEIGHT * K.GRADE). Now this code succesfully returns top 40 elements. However, i don't want E.NODE2 to return duplicates. POSTGRE SQL allowed me to do SELECT DISTINCT ON (NODE2) E.NODE2 , (E.WEIGHT * K.GRADE). How can i do the same in oracle?
The complete sql query;
SELECT *
FROM (SELECT DISTINCT E.NODE2 , (E.WEIGHT * K.GRADE)
FROM KUAISFAST K, EDGES E
WHERE K.ID = 1 AND K.COURSE_ID = E.NODE1 AND E.NODE2 NOT IN(
SELECT K2.COURSE_ID
FROM KUAISFAST K2
WHERE K2.ID = 1
)
ORDER BY( E.WEIGHT * K.GRADE ) DESC) TEMP
WHERE rownum <= 40
