Combine All Products

Coddy SQL 여정의 기초 섹션에 포함된 레슨 — 72개 중 55번째.

챌린지

중급

사용 가능한 테이블 및 열:
enom_gilpane: part_id, rpm, watt, size
castle_loctus: part_id, rpm, watt, size
honpan_bilopsa: part_id, rpm, watt, size
yurnol_qoltam: part_id, rpm, watt, size

이제 모든 제품(각 테이블은 하나의 제품)에 대해 동일한 품질을 계산하고 UNION ALL을 사용하여 모두 결합하세요:

quality_table as (
    SELECT * FROM filtered_quality_1
    UNION ALL
    SELECT * FROM filtered_quality_2
    UNION ALL 
    SELECT * FROM filtered_quality_3
    UNION ALL 
    SELECT * FROM filtered_quality_4
)

part_id와 quality를 반환하세요

직접 해보기

SELECT part_id, AVG(quality) AS quality
FROM (
    SELECT part_id, AVG(quality) AS quality
    FROM (
        SELECT part_id, (rpm * (watt + (SELECT AVG(watt) FROM enom_gilpane)) / size) as quality
        FROM enom_gilpane
    )
    GROUP BY part_id
    HAVING quality > AVG(quality)
    UNION ALL
    SELECT part_id, AVG(quality) AS quality
    FROM (
        SELECT part_id, (rpm * (watt + (SELECT AVG(watt) FROM castle_loctus)) / size) as quality
        FROM castle_loctus
    )
    GROUP BY part_id
    HAVING quality > AVG(quality)
    UNION ALL
    SELECT part_id, AVG(quality) AS quality
    FROM (
        SELECT part_id, (rpm * (watt + (SELECT AVG(watt) FROM honpan_bilopsa)) / size) as quality
        FROM honpan_bilopsa
    )
    GROUP BY part_id
    HAVING quality > AVG(quality)
    UNION ALL
    SELECT part_id, AVG(quality) AS quality
    FROM (
        SELECT part_id, (rpm * (watt + (SELECT AVG(watt) FROM yurnol_qoltam)) / size) as quality
        FROM yurnol_qoltam
    )
    GROUP BY part_id
    HAVING quality > AVG(quality)
)
GROUP BY part_id
ORDER BY quality DESC