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  1. MariaDB Server
  2. MDEV-6884

greatest and coalesce on null date does not produce null

        Details

        • Type: Bug
        • Status: Open
        • Priority: Minor
        • Resolution: Unresolved
        • Affects Version/s: 5.5.40, 10.0.14
        • Fix Version/s: 10.0
        • Component/s: OTHER
        • Labels:
          None

          Description

          I create a table and insert one row like this:

          create table datetest (nr decimal(1), date1 date);
insert into datetest values (1,null);

          The bug can be reproduced with this statement:

          least(coalesce(date1), coalesce(date1))

          this should return null, but it doesnt.
          E.g.

          select * from datetest where least(coalesce(date1), coalesce(date1)) is not null;

          ==> Returns one row

          It is also possible to insert this "corrupt null" into a table:

          insert into datetest select 2, least(coalesce(date1), coalesce(date1))  from datetest;

          if you select from this table with a select * from datetest where date1 is not null, you will get the row with nr=2

          Additional info:
          I get the same error using "greatest" instead of "least".
          I get the same error if I use more than one parameter for coalesce.
          I do not get this error if I use another datataype, like varchar instead of date.
          I do not get this error on another database like oracle 11g.

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                elenst Elena Stepanova added a comment -

                Thanks for the report.

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                elenst Elena Stepanova added a comment - Thanks for the report.

                  People

                  • Assignee:
                    bar Alexander Barkov
                    Reporter:
                    Sektat Marcel Schneider
                  • Votes:
                    1 Vote for this issue
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                    4 Start watching this issue

                    Dates

                    • Created:
                      Updated: