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  1. MariaDB Server
  2. MDEV-8707

Wrong result for SELECT..WHERE varchar_column=DATE'2001-01-01' AND varchar_column='2001-01-01'

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      Description

      DROP TABLE IF EXISTS t1;
      CREATE TABLE t1 (a VARCHAR(40));
      INSERT INTO t1 VALUES ('2001-01-01'),('2001-01-01x');
      SELECT * FROM t1 WHERE a=DATE'2001-01-01' AND a='2001-01-01';

      returns:

      +-------------+
      | a           |
      +-------------+
      | 2001-01-01  |
      | 2001-01-01x |
      +-------------+

      The second row is obviously wrong.

      If I write WHERE the other way round:

      SELECT * FROM t1 WHERE a='2001-01-01' AND a=DATE'2001-01-01';

      it works fine and correctly returns one row:

      +------------+
      | a          |
      +------------+
      | 2001-01-01 |
      +------------+

      The same problem is repeatable with ENUM type:

      DROP TABLE IF EXISTS t1;
      CREATE TABLE t1 (a ENUM('2001-01-01','2001-01-01x'));
      INSERT INTO t1 VALUES ('2001-01-01'),('2001-01-01x');
      SELECT * FROM t1 WHERE a=DATE'2001-01-01' AND a='2001-01-01';
      SELECT * FROM t1 WHERE a='2001-01-01' AND a=DATE'2001-01-01';

      Another example using ROW syntax:

      DROP TABLE IF EXISTS t1;
      CREATE TABLE t1 (a VARCHAR(20));
      INSERT INTO t1 VALUES ('2001-01-01x'),('2001-01-01');
      SELECT * FROM t1 WHERE (a,a)=('2001-01-01x',DATE'2001-01-01');
      SELECT * FROM t1 WHERE (a,a)=(DATE'2001-01-01','2001-01-01x')

      The first query correctly returns one row, the second query erroneously returns two rows.

      Another example:

      DROP TABLE IF EXISTS t1;
      CREATE TABLE t1 (a VARCHAR(40),b VARCHAR(40));
      INSERT INTO t1 VALUES ('2001-01-01','2001-01-01x');
      SELECT * FROM t1 WHERE a=b AND a=DATE'2001-01-01';

      returns:

      +------------+-------------+
      | a          | b           |
      +------------+-------------+
      | 2001-01-01 | 2001-01-01x |
      +------------+-------------+

      This is wrong. The expected result is empty set.

      The same problem happens with ENUM:

      DROP TABLE IF EXISTS t1;
      CREATE TABLE t1 (a ENUM('2001-01-01','2001-01-01x'),b ENUM('2001-01-01','2001-01-01x'));
      INSERT INTO t1 VALUES ('2001-01-01','2001-01-01x');
      SELECT * FROM t1 WHERE a=b AND a=DATE'2001-01-01';

      It erroneously returns one row. The expected result it to return no rows.

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              • Assignee:
                bar Alexander Barkov
                Reporter:
                bar Alexander Barkov
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                • Created:
                  Updated:
                  Resolved: