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  1. MariaDB Server
  2. MDEV-9495

Wrong field type for a UNION of a signed and an unsigned INT expression

Details

    • Bug
    • Status: Closed (View Workflow)
    • Major
    • Resolution: Fixed
    • 10.0(EOL), 10.1(EOL), 10.2(EOL)
    • 10.3.1
    • OTHER

    Description

      CREATE OR REPLACE TABLE t1 (a INT, b INT UNSIGNED);
      		 
      INSERT INTO t1 VALUES (0x7FFFFFFF,0xFFFFFFFF);
      		 
      CREATE OR REPLACE TABLE t2 AS SELECT a FROM t1 UNION SELECT b FROM t1;
      		 
      SHOW CREATE TABLE t2;
      		 
      SELECT * FROM t2;

      returns

      +-------+---------------------------------------------------------------------------------------+
      		 
      | Table | Create Table                                                                          |
      		 
      +-------+---------------------------------------------------------------------------------------+
      		 
      | t2    | CREATE TABLE `t2` (
      		 
        `a` int(11) DEFAULT NULL
      		 
      ) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
      		 
      +-------+---------------------------------------------------------------------------------------+

      This is wrong, as huge positive unsigned values are converted to negative values:

      +------------+
      		 
      | a          |
      		 
      +------------+
      		 
      | 2147483647 |
      		 
      |         -1 |
      		 
      +------------+

      Note, unlike UNION, hybrid functions aggregate data types correctly:

      CREATE OR REPLACE TABLE t1 (a INT, b INT UNSIGNED);
      		 
      INSERT INTO t1 VALUES (0x7FFFFFFF,0xFFFFFFFF);
      		 
      CREATE OR REPLACE TABLE t2 AS SELECT COALESCE(a,b), COALESCE(b,a) FROM t1;
      		 
      SHOW CREATE TABLE t2;
      		 
      SELECT * FROM t2;

      returns

      +-------+-------------------------------------------------------------------------------------------------------------------------------------------------------+
      		 
      | Table | Create Table                                                                                                                                          |
      		 
      +-------+-------------------------------------------------------------------------------------------------------------------------------------------------------+
      		 
      | t2    | CREATE TABLE `t2` (
      		 
        `COALESCE(a,b)` decimal(10,0) DEFAULT NULL,
      		 
        `COALESCE(b,a)` decimal(10,0) DEFAULT NULL
      		 
      ) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
      		 
      +-------+-------------------------------------------------------------------------------------------------------------------------------------------------------+

      and the values are preserved:

      +---------------+---------------+
      		 
      | COALESCE(a,b) | COALESCE(b,a) |
      		 
      +---------------+---------------+
      		 
      |    2147483647 |    4294967295 |
      		 
      +---------------+---------------+

      Attachments

        Issue Links

          blocks

          Epic - Created by Jira Software - do not edit or delete. Issue type for a big user story that needs to be broken down. MDEV-4912 Data type plugin API version 1

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Closed
          is duplicated by

          Bug - A problem which impairs or prevents the functions of the product. MDEV-14933 Wrong result caused by UNSIGNED column and UNION ALL

          • Major - Major loss of function.
          • Closed
          relates to

          Task - A task that needs to be done. MDEV-12775 Reuse data type aggregation code for hybrid functions and UNION

          • Major - Major loss of function.
          • Closed

          Activity

            People

              bar Alexander Barkov
              bar Alexander Barkov
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              Dates

                Created:
                Updated:
                Resolved:

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