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  1. MariaDB Server
  2. MDEV-12780

Spurious results for a CONCAT statement that contains a CASE statement inside.



      I have detected a query that contains subqueries with joins, concats and cases statements that generates spurious results.

      The problem is that the field computed by the CONCAT statement is living a bug related to the string management, overflow or something similar that causes outputs as the contained in the result.txt attached file.

      I have attached 4 files:

      • saltos.sql => contains a minimum schema and sufficient data to reproduce the issue.
      • query.sql => contains a simple query able to demostrate the problem.
      • result.txt => contains the result of execute the query.sql into saltos.sql.
      • expected.txt => contains the expected result.

      As a note:

      If you remove the WHERE statement or replace the "d.id id_usuario" by "e.id_usuario id_usuario" in the fields zone of the SELECT, then you get the expected result.

      I have tryed other versions of MariaDB. I have reproduced the issue in the follows releases: 10.1.14, 10.1.16, 10.1.21, 10.1.22 and 10.1.23



        1. expected.txt
          0.2 kB
        2. query.sql
          0.6 kB
        3. result.txt
          0.5 kB
        4. saltos.sql
          9 kB



            • Assignee:
              sanja Oleksandr Byelkin
              sanz Josep Sanz
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