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  1. MariaDB Server
  2. MDEV-16926

CAST(COALESCE(year_field)) returns wrong value

Details

    • Bug
    • Status: Closed (View Workflow)
    • Major
    • Resolution: Fixed
    • 10.0(EOL), 10.1(EOL), 10.2(EOL), 10.3(EOL), 10.4(EOL)
    • 10.4.0
    • Data types, Temporal Types
    • None

    Description

      This script:

      CREATE OR REPLACE TABLE t1 (a YEAR);
      		 
      INSERT INTO t1 VALUES (2000);
      		 
      SELECT CAST(a AS DATE), CAST(COALESCE(a) AS DATE) FROM t1;
      		 
      SHOW WARNINGS;

      produces the following output:

      +-----------------+---------------------------+
      		 
      | CAST(a AS DATE) | CAST(COALESCE(a) AS DATE) |
      		 
      +-----------------+---------------------------+
      		 
      | 2000-00-00      | NULL                      |
      		 
      +-----------------+---------------------------+
      		 
      1 row in set, 1 warning (0.00 sec)
      		 
       
      		 
      +---------+------+----------------------------------+
      		 
      | Level   | Code | Message                          |
      		 
      +---------+------+----------------------------------+
      		 
      | Warning | 1292 | Incorrect datetime value: '2000' |
      		 
      +---------+------+----------------------------------+

      NULL in the second column is wrong. Both columns should return the same value, without warnings.

      This happens because Type_handler_year has a special implementation in Item_get_date():

      bool Type_handler_year::Item_get_date(Item *item, MYSQL_TIME *ltime,
      		 
                                                   ulonglong fuzzydate) const
      		 
      {
      		 
        return item->get_date_from_year(ltime, fuzzydate);
      		 
      }

      but does not have a similar implementation for Item_func_hybrid_field_type_get_date().

      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
          relates to

          Bug - A problem which impairs or prevents the functions of the product. MDEV-8284 Comparison of YEAR to '1970' is not consistent

          • Major - Major loss of function.
          • Open

          Bug - A problem which impairs or prevents the functions of the product. MDEV-9343 Copying from YEAR to DATE result in '0000-00-00'

          • Critical - Crashes, loss of data, severe memory leak.
          • In Review

          Bug - A problem which impairs or prevents the functions of the product. MDEV-17607 DATE(COALESCE(year_column)) returns a wrong result

          • 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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