Combine All Products

Part of the Fundamentals section of Coddy's SQL journey. Lesson 55 of 72.

Challenge

Medium

Available tables and columns:
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

Now calculate the same quality for all products (Each table is a product) and combine them all using 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
)

Return part_id and quality

Try it yourself

-- The first product block is done for you, carried over from the last lesson
WITH filtered_enom_gilpane_quality as (
    WITH enom_gilpane_quality as (
        SELECT part_id, ((rpm * watt) / size) as quality
        FROM (
            SELECT part_id, rpm, watt + (select avg(watt) from enom_gilpane) as watt, size
            FROM enom_gilpane
        )
    )

    SELECT *
    FROM enom_gilpane_quality
    WHERE quality > (select avg(quality) from enom_gilpane_quality)
),
-- Build the same block for each of the three product tables below
filtered_castle_loctus_quality as (
    ____
),
filtered_honpan_bilopsa_quality as (
    ____
),
filtered_yurnol_qoltam_quality as (
    ____
),
-- Stack the four blocks on top of each other, keeping every row
quality_table as (
    SELECT * FROM filtered_enom_gilpane_quality
    ____
)

SELECT ____
FROM quality_table