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  1. MariaDB Server
  2. MDEV-8688

Wrong result for SELECT..WHERE varchar_column IN (1,2,3) AND varchar_column=' 1';

Details

    Description

      This script:

      DROP TABLE IF EXISTS t1;
      		 
      CREATE TABLE t1 (a VARCHAR(10) CHARACTER SET cp1251 COLLATE cp1251_ukrainian_ci);
      		 
      INSERT INTO t1 VALUES (' 1'),('`1');
      		 
      SELECT * FROM t1 WHERE a IN (1,2,3);

      returns one row:

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

      Now if I make the condition even stroger:

      SELECT * FROM t1 WHERE a IN (1,2,3) AND a=' 1';

      It erroneously returns two rows:

      +------+
      		 
      | a    |
      		 
      +------+
      		 
      |  1   |
      		 
      | `1   |
      		 
      +------+

      It should return one row.

      The problem happens in equal fields propagation in this code:

        if (!item || !has_compatible_context(item))
      		 
          item= this;

      Item_func_in does not set cmp_type of args[0], so has_compatible_context() passes and the field gets erroneously replaced to the string constant which makes Item_func_in::val_int() always evaluate to TRUE.

      Attachments

        Issue Links

          blocks

          Bug - A problem which impairs or prevents the functions of the product. MDEV-8728 Fix a number of problems in equal field and equal expression propagation

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

          Activity

            Ascending order - Click to sort in descending order
            bar Alexander Barkov created issue -
            bar Alexander Barkov added a comment -

            Another example script:

            SET NAMES utf8;
            		 
            DROP TABLE IF EXISTS t1;
            		 
            CREATE TABLE t1 (a VARCHAR(10) CHARACTER SET latin1);
            		 
            INSERT INTO t1 VALUES ('1e1'),('1ë1');
            		 
            SELECT * FROM t1 WHERE a IN (1,2);

            returns one row:

            +------+
            		 
            | a    |
            		 
            +------+
            		 
            | 1ë1  |
            		 
            +------+

            Now if I make the condition even stronger:

            SELECT * FROM t1 WHERE a IN (1,2) AND a='1ë1';

            it erroneously returns two rows:

            +------+
            		 
            | a    |
            		 
            +------+
            		 
            | 1e1  |
            		 
            | 1ë1  |
            		 
            +------+

            bar Alexander Barkov added a comment - Another example script: SET NAMES utf8; DROP TABLE IF EXISTS t1; CREATE TABLE t1 (a VARCHAR(10) CHARACTER SET latin1); INSERT INTO t1 VALUES ('1e1'),('1ë1'); SELECT * FROM t1 WHERE a IN (1,2); returns one row: +------+ | a | +------+ | 1ë1 | +------+ Now if I make the condition even stronger: SELECT * FROM t1 WHERE a IN (1,2) AND a='1ë1'; it erroneously returns two rows: +------+ | a | +------+ | 1e1 | | 1ë1 | +------+
            elenst Elena Stepanova made changes -
            Field Original Value New Value
            Affects Version/s 5.3.12 [ 12000 ]
            Affects Version/s 5.2.14 [ 12101 ]
            Affects Version/s 5.1.67 [ 12100 ]
            Affects Version/s 10.1 [ 16100 ]
            Affects Version/s 10.0 [ 16000 ]
            Affects Version/s 5.5 [ 15800 ]
            Labels upstream
            bar Alexander Barkov made changes -
            Fix Version/s 10.0 [ 16000 ]
            Fix Version/s 5.5 [ 15800 ]
            bar Alexander Barkov made changes -
            Fix Version/s 10.1.7 [ 19604 ]
            Fix Version/s 10.1 [ 16100 ]
            Resolution Fixed [ 1 ]
            Status Open [ 1 ] Closed [ 6 ]
            bar Alexander Barkov made changes -
            bar Alexander Barkov made changes -
            Labels upstream propagation upstream
            serg Sergei Golubchik made changes -
            Workflow MariaDB v3 [ 71231 ] MariaDB v4 [ 149524 ]

            People

              bar Alexander Barkov
              bar Alexander Barkov
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              Dates

                Created:
                Updated:
                Resolved:

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