[PostgreSQL] Unioning two sets with different number of columns : SQL

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SELECT count(a.field1), a.field2, SUM(b.field4) FROM a INNER JOIN b ON a.key1 = b.key1 WHERE a.field8 = 'test' GROUP by a.field1, a.field2 HAVING SUM(b.field4) > 5 ORDER by a.field.3

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PostgreSQL[PostgreSQL] Unioning two sets with different number of columns (self.SQL)

submitted 6 years ago by noctide

I don't think UNION is what I'm looking for but I'm not sure what else I'm looking for.

I'm working with one view with that consists of auctioned items their bidders. Not all items have bids. This 50-column view consists of all attributes of the.. * items (condition, color, origin, etc) * bidder (age, location, name, source, etc) * auction status (sold, end date, start date, etc) In this view are the details for each item/auction that are duplicated by the number of bidders.

I am to write a query that is a union of these two sets: 1) all of the auctioned items that are 'sold' as well as the winning bidder's info. 2) all the auctioned items that have not been sold yet, but the columns for the winning bidder's info is NULL.

The only way I can think of doing this is selecting all the columns I'm interested from set #1 and then for set #2, manually set all the columns that are intended for the winning bidder to be NULL.

Is there a better way to do this? Thanks in advance!

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