使用新的别名列作为键联接表

Question

When I try to join 2 tables with my data, I get an error that my reference is ambiguous or I get the order that my original table does not have the alias column.

This is among my first projects with sql and an important learning point for me so I appreciate the guidance.

Here is my code.

WITH 
RentDotComOnly AS
(
  SELECT 
    concat(DATE_PART(mm,archived_apartments.week),clean_zip) AS "monthlyzip",
    COUNT(clean_zip) AS "rent_count_clean_zip", 
    AVG((low_price+high_price)/2) AS "rent_avg_price", 0.85*min(low_price) AS "rent_lower_bound", 1.15*max(high_price) AS "rent_upper_bound"
  FROM 
    archived_apartments 
  WHERE 
    source_type in (29,36,316) 
    AND week between '2015-07-06' and '2015-10-12' 
    AND is_house <> 1  
    AND archived_apartments.high_price <> 0 
  GROUP BY monthlyzip
),
AllRJData AS
(
  SELECT
    concat(DATEPART(mm,archived_apartments.week),clean_zip) AS "monthlyzip",
    COUNT(clean_zip) AS "all_count_clean_zip", 
    AVG((low_price+high_price)/2) AS "all_avg_price"
  FROM 
    archived_apartments 
  WHERE 
    week between '2015-07-06' and '2015-10-12' 
    AND is_house <> 1  
  GROUP BY monthlyzip
)
SELECT 
  concat(DATE_PART(mm,archived_apartments.week),clean_zip) AS "monthlyzip",
  COUNT(archived_apartments.clean_zip) as filtered_count_clean_zip, 
  RentDotComOnly.rent_count_clean_zip, RentDotComOnly.rent_avg_price, RentDotComOnly.rent_lower_bound, RentDotComOnly.rent_upper_bound,
  AllRjData.all_count_clean_zip, AllRjData.all_avg_price
FROM
archived_apartments 
JOIN AllRJData 
ON concat(DATE_PART(mm,archived_apartments.week),archived_apartments.clean_zip) = AllRJData.monthlyzip
JOIN RentDotComOnly
ON concat(DATE_PART(mm,archived_apartments.week),archived_apartments.clean_zip) = RentDotComOnly.monthlyzip
WHERE 
  archived_apartments.week between '2015-07-06' and '2015-10-12'
  AND archived_apartments.is_house <> 1 
  AND archived_apartments.high_price <> 0 
  AND archived_apartments.low_price > RentDotComOnly.rent_lower_bound
  OR archived_apartments.high_price < RentDotComOnly.rent_upper_bound
  AND archived_apartments.week between '2015-07-06' and '2015-10-12'
  AND archived_apartments.is_house <> 1 
  AND archived_apartments.high_price <> 0 
GROUP BY monthlyzip
RentDotComOnly.rent_count_clean_zip, RentDotComOnly.rent_avg_price, RentDotComOnly.rent_lower_bound, RentDotComOnly.rent_upper_bound, 
AllRjData.all_count_clean_zip, AllRjData.all_avg_price
ORDER BY monthlyzip

Answer 1

The problem is that the monthlyzip column you are referring to in your join is ambiguous. You have three tables with that column, which table are you referring to?

If monthly_zip existed on archived_apartments you could do:

FROM
archived_apartments JOIN
AllRJData 
ON archived_apartments.monthlyzip = AllRJData.monthlyzip
JOIN RentDotComOnly 
ON archived_apartments.monthlyzip = RentDotComOnly.monthlyzip

But it sounds like monthly_zip doesn't exist in archived_apartments so you can't actually join on that field. Instead you have to join on the formula you used to make monthlyzip :

FROM
archived_apartments JOIN
AllRJData 
ON concat(DATEPART(mm,archived_apartments.week),archived_apartment.clean_zip)  = AllRJData.monthlyzip
JOIN RentDotComOnly 
ON concat(DATEPART(mm,archived_apartments.week),archived_apartment.clean_zip)  = RentDotComOnly.monthlyzip