Combine All Products

Teil des Abschnitts Grundlagen der SQL-Journey von Coddy — Lektion 55 von 72.

Aufgabe

Mittel

Verfügbare Tabellen und Spalten:
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

Berechnen Sie nun dieselbe Qualität für alle Produkte (Jede Tabelle ist ein Produkt) und kombinieren Sie sie alle mit UNION ALL:

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
)

Geben Sie part_id und quality zurück

Probier es selbst

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