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  1. MariaDB Server
  2. MDEV-6302

Wrong result set when using GROUP BY FROM_UNIXTIME(...)+0

Details

    • Bug
    • Status: Closed (View Workflow)
    • Major
    • Resolution: Fixed
    • 5.3.12, 5.5.37, 10.0.11
    • 5.5.39, 10.0.13, 5.3.13
    • None
    • None

    Description

      This script returns from results:

      DROP TABLE IF EXISTS t1;
      		 
      CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
      		 
      INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
      		 
      SELECT a, FROM_UNIXTIME(CONCAT(a,'10')) AS f1, FROM_UNIXTIME(CONCAT(a,'10'))+0 AS f2 FROM t1;
      		 
      SELECT * FROM t1 GROUP BY FROM_UNIXTIME(CONCAT(a,'10'))+0;

      The first SELECT returns:

      +------------+---------------------+------------------------------------------------+
      		 
      | a          | f1                  | f2                                             |
      		 
      +------------+---------------------+------------------------------------------------+
      		 
      | 2005-05-04 | 1970-01-01 03:33:25 | 19700101033325.0000000000000000000000000000000 |
      		 
      | 2000-02-23 | 1970-01-01 03:33:20 | 19700101033320.0000000000000000000000000000000 |
      		 
      +------------+---------------------+------------------------------------------------+

      Notice, the number of fractional digits in "f2" looks excessive.

      The second SELECT returns:

      +------------+
      		 
      | a          |
      		 
      +------------+
      		 
      | 2005-05-04 |
      		 
      +------------+

      This is wrong, because the two values in "f2" in the previous SELECT
      are unique. The expected result in this SELECT should return two rows.

      More similar failures:

      DROP TABLE IF EXISTS t1;
      		 
      CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
      		 
      INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
      		 
      SELECT * FROM t1 GROUP BY FROM_UNIXTIME(concat(a,'10'))/1;

      A related problem:

      DROP TABLE IF EXISTS t1,t2;
      		 
      CREATE TABLE t1 (a DATE);
      		 
      INSERT INTO t1 VALUES ('2005-05-04');
      		 
      SELECT CHAR_LENGTH(CONCAT(FROM_UNIXTIME(CONCAT(a,'10')) MOD FROM_UNIXTIME(CONCAT(a,'10')))) AS f2 FROM t1; 
      CREATE TABLE t2 AS SELECT CONCAT(FROM_UNIXTIME(CONCAT(a,'10')) MOD FROM_UNIXTIME(CONCAT(a,'10'))) AS f2 FROM t1;
      		 
      SHOW WARNINGS;
      		 
      SHOW COLUMNS IN t2;

      returns warnings:

      +---------+------+-----------------------------------------+
      		 
      | Level   | Code | Message                                 |
      		 
      +---------+------+-----------------------------------------+
      		 
      | Warning | 1265 | Data truncated for column 'f2' at row 1 |
      		 
      +---------+------+-----------------------------------------+

      which happens because the column is too short (26),
      while CHAR_LENGTH() in the above query returns 27:

      +-------+---------------+------+-----+---------+-------+
      		 
      | Field | Type          | Null | Key | Default | Extra |
      		 
      +-------+---------------+------+-----+---------+-------+
      		 
      | f2    | varbinary(26) | YES  |     | NULL    |       |
      		 
      +-------+---------------+------+-----+---------+-------+

      Attachments

        Activity

          Ascending order - Click to sort in descending order
          bar Alexander Barkov created issue -
          serg Sergei Golubchik made changes -
          Field Original Value New Value
          Description {code:sql}
          {code}

          This script returns from results:
          {code:sql}
          DROP TABLE IF EXISTS t1;
          CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
          INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
          SELECT a, FROM_UNIXTIME(CONCAT(a,'10')) AS f1, FROM_UNIXTIME(CONCAT(a,'10'))+0 AS f2 FROM t1;
          SELECT * FROM t1 GROUP BY FROM_UNIXTIME(CONCAT(a,'10'))+0;
          {code}

          The first SELECT returns:
          {noformat}
          +------------+---------------------+------------------------------------------------+
          | a | f1 | f2 |
          +------------+---------------------+------------------------------------------------+
          | 2005-05-04 | 1970-01-01 03:33:25 | 19700101033325.0000000000000000000000000000000 |
          | 2000-02-23 | 1970-01-01 03:33:20 | 19700101033320.0000000000000000000000000000000 |
          +------------+---------------------+------------------------------------------------+
          {noformat}
          Notice, the number of fractional digits in "f2" looks excessive.

          The second SELECT returns:
          {noformat}
          +------------+
          | a |
          +------------+
          | 2005-05-04 |
          +------------+
          {noformat}
          This is wrong, because the two values in "f2" in the previous SELECT
          are unique. The expected result in this SELECT should return two rows.
          		 This script returns from results:
          {code:sql}
          DROP TABLE IF EXISTS t1;
          CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
          INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
          SELECT a, FROM_UNIXTIME(CONCAT(a,'10')) AS f1, FROM_UNIXTIME(CONCAT(a,'10'))+0 AS f2 FROM t1;
          SELECT * FROM t1 GROUP BY FROM_UNIXTIME(CONCAT(a,'10'))+0;
          {code}

          The first SELECT returns:
          {noformat}
          +------------+---------------------+------------------------------------------------+
          | a | f1 | f2 |
          +------------+---------------------+------------------------------------------------+
          | 2005-05-04 | 1970-01-01 03:33:25 | 19700101033325.0000000000000000000000000000000 |
          | 2000-02-23 | 1970-01-01 03:33:20 | 19700101033320.0000000000000000000000000000000 |
          +------------+---------------------+------------------------------------------------+
          {noformat}
          Notice, the number of fractional digits in "f2" looks excessive.

          The second SELECT returns:
          {noformat}
          +------------+
          | a |
          +------------+
          | 2005-05-04 |
          +------------+
          {noformat}
          This is wrong, because the two values in "f2" in the previous SELECT
          are unique. The expected result in this SELECT should return two rows.
          bar Alexander Barkov made changes -
          Description This script returns from results:
          {code:sql}
          DROP TABLE IF EXISTS t1;
          CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
          INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
          SELECT a, FROM_UNIXTIME(CONCAT(a,'10')) AS f1, FROM_UNIXTIME(CONCAT(a,'10'))+0 AS f2 FROM t1;
          SELECT * FROM t1 GROUP BY FROM_UNIXTIME(CONCAT(a,'10'))+0;
          {code}

          The first SELECT returns:
          {noformat}
          +------------+---------------------+------------------------------------------------+
          | a | f1 | f2 |
          +------------+---------------------+------------------------------------------------+
          | 2005-05-04 | 1970-01-01 03:33:25 | 19700101033325.0000000000000000000000000000000 |
          | 2000-02-23 | 1970-01-01 03:33:20 | 19700101033320.0000000000000000000000000000000 |
          +------------+---------------------+------------------------------------------------+
          {noformat}
          Notice, the number of fractional digits in "f2" looks excessive.

          The second SELECT returns:
          {noformat}
          +------------+
          | a |
          +------------+
          | 2005-05-04 |
          +------------+
          {noformat}
          This is wrong, because the two values in "f2" in the previous SELECT
          are unique. The expected result in this SELECT should return two rows.
          		 This script returns from results:
          {code:sql}
          DROP TABLE IF EXISTS t1;
          CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
          INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
          SELECT a, FROM_UNIXTIME(CONCAT(a,'10')) AS f1, FROM_UNIXTIME(CONCAT(a,'10'))+0 AS f2 FROM t1;
          SELECT * FROM t1 GROUP BY FROM_UNIXTIME(CONCAT(a,'10'))+0;
          {code}

          The first SELECT returns:
          {noformat}
          +------------+---------------------+------------------------------------------------+
          | a | f1 | f2 |
          +------------+---------------------+------------------------------------------------+
          | 2005-05-04 | 1970-01-01 03:33:25 | 19700101033325.0000000000000000000000000000000 |
          | 2000-02-23 | 1970-01-01 03:33:20 | 19700101033320.0000000000000000000000000000000 |
          +------------+---------------------+------------------------------------------------+
          {noformat}
          Notice, the number of fractional digits in "f2" looks excessive.

          The second SELECT returns:
          {noformat}
          +------------+
          | a |
          +------------+
          | 2005-05-04 |
          +------------+
          {noformat}
          This is wrong, because the two values in "f2" in the previous SELECT
          are unique. The expected result in this SELECT should return two rows.

          More similar failures:
          {code}
          DROP TABLE IF EXISTS t1;
          CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
          INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
          SELECT * FROM t1 GROUP BY FROM_UNIXTIME(concat(a,'10'))/1;
          {code}
          bar Alexander Barkov made changes -
          Description This script returns from results:
          {code:sql}
          DROP TABLE IF EXISTS t1;
          CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
          INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
          SELECT a, FROM_UNIXTIME(CONCAT(a,'10')) AS f1, FROM_UNIXTIME(CONCAT(a,'10'))+0 AS f2 FROM t1;
          SELECT * FROM t1 GROUP BY FROM_UNIXTIME(CONCAT(a,'10'))+0;
          {code}

          The first SELECT returns:
          {noformat}
          +------------+---------------------+------------------------------------------------+
          | a | f1 | f2 |
          +------------+---------------------+------------------------------------------------+
          | 2005-05-04 | 1970-01-01 03:33:25 | 19700101033325.0000000000000000000000000000000 |
          | 2000-02-23 | 1970-01-01 03:33:20 | 19700101033320.0000000000000000000000000000000 |
          +------------+---------------------+------------------------------------------------+
          {noformat}
          Notice, the number of fractional digits in "f2" looks excessive.

          The second SELECT returns:
          {noformat}
          +------------+
          | a |
          +------------+
          | 2005-05-04 |
          +------------+
          {noformat}
          This is wrong, because the two values in "f2" in the previous SELECT
          are unique. The expected result in this SELECT should return two rows.

          More similar failures:
          {code}
          DROP TABLE IF EXISTS t1;
          CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
          INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
          SELECT * FROM t1 GROUP BY FROM_UNIXTIME(concat(a,'10'))/1;
          {code}
          		 This script returns from results:
          {code:sql}
          DROP TABLE IF EXISTS t1;
          CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
          INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
          SELECT a, FROM_UNIXTIME(CONCAT(a,'10')) AS f1, FROM_UNIXTIME(CONCAT(a,'10'))+0 AS f2 FROM t1;
          SELECT * FROM t1 GROUP BY FROM_UNIXTIME(CONCAT(a,'10'))+0;
          {code}

          The first SELECT returns:
          {noformat}
          +------------+---------------------+------------------------------------------------+
          | a | f1 | f2 |
          +------------+---------------------+------------------------------------------------+
          | 2005-05-04 | 1970-01-01 03:33:25 | 19700101033325.0000000000000000000000000000000 |
          | 2000-02-23 | 1970-01-01 03:33:20 | 19700101033320.0000000000000000000000000000000 |
          +------------+---------------------+------------------------------------------------+
          {noformat}
          Notice, the number of fractional digits in "f2" looks excessive.

          The second SELECT returns:
          {noformat}
          +------------+
          | a |
          +------------+
          | 2005-05-04 |
          +------------+
          {noformat}
          This is wrong, because the two values in "f2" in the previous SELECT
          are unique. The expected result in this SELECT should return two rows.

          More similar failures:
          {code}
          DROP TABLE IF EXISTS t1;
          CREATE TABLE t1 (a DATE) ENGINE=MyISAM;
          INSERT INTO t1 VALUES ('2005-05-04'),('2000-02-23');
          SELECT * FROM t1 GROUP BY FROM_UNIXTIME(concat(a,'10'))/1;
          {code}


          A related problem:
          {code}
          DROP TABLE IF EXISTS t1,t2;
          CREATE TABLE t1 (a DATE);
          INSERT INTO t1 VALUES ('2005-05-04');
          SELECT CHAR_LENGTH(CONCAT(FROM_UNIXTIME(CONCAT(a,'10')) MOD FROM_UNIXTIME(CONCAT(a,'10')))) AS f2 FROM t1;
          CREATE TABLE t2 AS SELECT CONCAT(FROM_UNIXTIME(CONCAT(a,'10')) MOD FROM_UNIXTIME(CONCAT(a,'10'))) AS f2 FROM t1;
          SHOW WARNINGS;
          SHOW COLUMNS IN t2;
          {code}

          returns warnings:
          {code}
          +---------+------+-----------------------------------------+
          | Level | Code | Message |
          +---------+------+-----------------------------------------+
          | Warning | 1265 | Data truncated for column 'f2' at row 1 |
          +---------+------+-----------------------------------------+
          {code}

          which happens because the column is too short (26),
          while CHAR_LENGTH() in the above query returns 27:
          {code}
          +-------+---------------+------+-----+---------+-------+
          | Field | Type | Null | Key | Default | Extra |
          +-------+---------------+------+-----+---------+-------+
          | f2 | varbinary(26) | YES | | NULL | |
          +-------+---------------+------+-----+---------+-------+
          {code}
          serg Sergei Golubchik made changes -
          Workflow defaullt [ 41901 ] MariaDB v2 [ 44349 ]
          serg Sergei Golubchik made changes -
          Fix Version/s 10.0.13 [ 16000 ]
          Fix Version/s 10.0.12 [ 15201 ]
          bar Alexander Barkov made changes -
          Resolution Fixed [ 1 ]
          Status Open [ 1 ] Closed [ 6 ]
          serg Sergei Golubchik made changes -
          Fix Version/s 10.0.13 [ 16300 ]
          Fix Version/s 5.5 [ 15800 ]
          Fix Version/s 10.0 [ 16000 ]
          serg Sergei Golubchik made changes -
          Fix Version/s 5.5.39 [ 16301 ]
          ratzpo Rasmus Johansson (Inactive) made changes -
          Workflow MariaDB v2 [ 44349 ] MariaDB v3 [ 64324 ]
          serg Sergei Golubchik made changes -
          Workflow MariaDB v3 [ 64324 ] MariaDB v4 [ 147933 ]

          People

            bar Alexander Barkov
            bar Alexander Barkov
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            Dates

              Created:
              Updated:
              Resolved:

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