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Artifact ID: 419e98d5f5ceb62153429e772af7f0d3a6bf9a049be4e45a35316e7bf335f6b6
Ticket: c4130c33be081b2e75e8eb12b623ff6b67752ed0
DISTINCT malfunctions for VIEW
User & Date: drh 2019-09-10 19:46:38
Changes

  1. Change icomment to:

    0 is not distinct from 0.0 since (0 IS 0.0) IS TRUE. So the query

    SELECT DISTINCT * FROM (VALUES(0),(0.0));
    

    Is free to return either 0 or 0.0. The choice is arbitrary. It is analogous to a SELECT with a "LIMIT 1" and without an ORDER BY clause in that the query is free to return any single row that it wants.

    If the query decides to return 0, then 0||0.1 is a string '00.1' which evaluates to TRUE. If the query decides to return 0.0, then 0.0||0.1 is a string '0.00.1' which evaluates to false. So the other queries in the original problem statement are free to return either result depending on which value comes out of the ambiguous view.

  2. Change login to "drh"
  3. Change mimetype to "text/x-fossil-wiki"
  4. Change priority to "Immediate"
  5. Change resolution to "Not_A_Bug"
  6. Change status to "Closed"
  7. Change subsystem to "Unknown"