使用 DISTINCT 和 UNION 函数后如何获取 SQL 中的所有列？

Question

I am trying to write a Query that will combine historical appointment data with live-updating appointment data.

The Live Updating Data and Historical Data have all common column headers and data types.

The Historical Data set is a static snapshot of 100k-150k rows of data which I am trying to UNION with the Live-Updating Data to create a Full Data Set

Since there is some overlap between the Live-Updating Data and the Historical Data, I want to filter out Distinct appointment ID's

---

Here is the query that I've written:

SELECT
DISTINCT(n.appointment_id)
FROM (
  SELECT 
  * FROM note_data
  UNION
  SELECT * FROM note_data_historical) as n

FULL OUTER JOIN note_data_historical as historical
    on historical.appointment_id = n.appointment_id
  
FULL OUTER JOIN note_data as live
    on live.appointment_id = n.appointment_id

What I am trying to do is to avoid having to write out the couple of dozen column headers, but also not have duplicate rows.

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So to summarize, I would like to:

1. Join Two Data Sets with Overlapping Rows to Get a Complete Data Set
2. Filter out Overlapping Rows
3. Get all of the columns to appear (like a SELECT * grouped by or joined on one column)

Answer 1

It sounds like you want something like the following

SELECT * 
FROM note_data
UNION ALL
SELECT * 
FROM note_data_historical
WHERE note_data_historical.appointment_id NOT IN
(
 SELECT appointment_id FROM note_data
)

This gets all of your note_data and note_data_historical rows, unless the note_data_historical.appointment_id exists in note_data. And you don't need to list the columns in your query.

Note that I used a UNION ALL instead of a UNION , but since I don't know your data, I don't know if that's actually reasonable.