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  1. MariaDB Server
  2. MDEV-12505

Wrong data type for GREATEST(bit_column, int_column)

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    Details

    • Type: Bug
    • Status: Closed (View Workflow)
    • Priority: Major
    • Resolution: Duplicate
    • Affects Version/s: 10.0
    • Fix Version/s: 10.1.8
    • Component/s: OTHER
    • Labels:
      None

      Description

      This problem was earlier fixed in 10.1 and is not really repeatable in 10.2.

      DROP TABLE IF EXISTS t1;
      CREATE TABLE t1 (a BIT(64),b INT);
      INSERT INTO t1 VALUES (0xFFFFFFFFFFFFFFFF,-1);
      SELECT a>b, GREATEST(a,b) FROM t1;
      

      +------+---------------+
      | a>b  | GREATEST(a,b) |
      +------+---------------+
      |    1 | -1            |
      +------+---------------+
      

      The value of the first column looks good, as BIT is treated like a unsigned number, according to design.
      The value of the second column is wrong. It should return 18446744073709551615.

      Now I do:

      DROP TABLE IF EXISTS t2;
      CREATE TABLE t2 AS SELECT COALESCE(a,b),GREATEST(a,b) FROM t1;
      SELECT * FROM t2;
      

      +----------------------+---------------+
      | COALESCE(a,b)        | GREATEST(a,b) |
      +----------------------+---------------+
      | 18446744073709551615 |            -1 |
      +----------------------+---------------+
      

      The value of the first column with COALESCE is correct.
      The value of the first column with GREATEST is wrong.

      Now I check the table structure:

      SHOW CREATE TABLE t2;
      

      +-------+----------------------------------------------------------------------------------------------------------------------------------------------------+
      | Table | Create Table                                                                                                                                       |
      +-------+----------------------------------------------------------------------------------------------------------------------------------------------------+
      | t2    | CREATE TABLE `t2` (
        `COALESCE(a,b)` decimal(64,0) DEFAULT NULL,
        `GREATEST(a,b)` bigint(65) DEFAULT NULL
      ) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
      +-------+----------------------------------------------------------------------------------------------------------------------------------------------------+
      

      The data type of the first column with COALESCE is correct.
      The data type of the second column with GREATEST is wrong.

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              Assignee:
              bar Alexander Barkov
              Reporter:
              bar Alexander Barkov
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                Dates

                Created:
                Updated:
                Resolved: