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  1. MariaDB Server
  2. MDEV-9408

CREATE TABLE SELECT MAX(int_column) creates different columns for table vs view

Details

    • Bug
    • Status: Closed (View Workflow)
    • Major
    • Resolution: Fixed
    • 5.5(EOL), 10.0(EOL), 10.1(EOL), 10.2(EOL)
    • 10.3.1
    • Data types, Views
    • None

    Description

      DROP TABLE IF EXISTS t1;
      		 
      CREATE TABLE t1 (
      		 
        id int(11) NOT NULL PRIMARY KEY,
      		 
        country varchar(32),
      		 
        code int(11) default NULL
      		 
      );
      		 
      INSERT INTO t1 VALUES (1,'ITALY',100),(2,'ITALY',200),(3,'FRANCE',100), (4,'ITALY',100);
      		 
      DROP VIEW IF EXISTS v1;
      		 
      CREATE VIEW v1 AS SELECT * FROM t1;
      		 
       
      		 
      DROP TABLE IF EXISTS t2;
      		 
      CREATE TABLE t2 AS
      		 
      SELECT code, COUNT(DISTINCT country), MAX(id) FROM t1 GROUP BY code ORDER BY MAX(id);
      		 
      SHOW CREATE TABLE t2;

      returns

      +-------+----------------------------------------------------------------------------------------------------------------------------------------------------------------+
      		 
      | Table | Create Table                                                                                                                                                   |
      		 
      +-------+----------------------------------------------------------------------------------------------------------------------------------------------------------------+
      		 
      | t2    | CREATE TABLE `t2` (
      		 
        `code` int(11) DEFAULT NULL,
      		 
        `COUNT(DISTINCT country)` bigint(21) NOT NULL,
      		 
        `MAX(id)` int(11)
      		 
      ) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
      		 
      +-------+----------------------------------------------------------------------------------------------------------------------------------------------------------------+

      Notice, MAX(id) was correctly created as INT(11) when doing CREATE..SELECT..FROM t1.

      Now if I do the same with v1 instead of t1:

      DROP TABLE IF EXISTS t2;
      		 
      CREATE TABLE t2 AS
      		 
      SELECT code, COUNT(DISTINCT country), MAX(id) FROM v1 GROUP BY code ORDER BY MAX(id);
      		 
      SHOW CREATE TABLE t2;

      it returns

      +-------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
      		 
      | Table | Create Table                                                                                                                                                                   |
      		 
      +-------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
      		 
      | t2    | CREATE TABLE `t2` (
      		 
        `code` int(11) DEFAULT NULL,
      		 
        `COUNT(DISTINCT country)` bigint(21) NOT NULL,
      		 
        `MAX(id)` bigint(11) DEFAULT NULL
      		 
      ) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
      		 
      +-------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

      Notice, MAX(id) was erroneously created as BIGINT(11).

      The problem happens because Item_sum::create_tmp_field() does not adjust the data type from length.

      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

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            People

              bar Alexander Barkov
              bar Alexander Barkov
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              Dates

                Created:
                Updated:
                Resolved:

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