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  1. MariaDB Server
  2. MDEV-9302

Different field types for equivalent NULLIF and IF vs CASE with AVG(int_field) and 0e0 arguments

Details

    • Bug
    • Status: Closed (View Workflow)
    • Major
    • Resolution: Not a Bug
    • 10.0(EOL), 10.1(EOL)
    • 10.0.23
    • OTHER
    • None

    Description

      This script:

      DROP TABLE IF EXISTS t1,t2;
      		 
      CREATE TABLE t1 (c1 INT DEFAULT NULL);
      		 
      INSERT INTO t1 (c1) VALUES (1),(2),(3),(4);
      		 
      CREATE TABLE t2
      		 
      SELECT
      		 
        NULLIF(AVG(c1),0e0) AS c1,
      		 
        IF(AVG(c1)=0e0,NULL,AVG(c1)) AS c2,
      		 
        CASE WHEN AVG(c1)=0e0 THEN 0e0 ELSE AVG(c1) END AS c3
      		 
      FROM t1;
      		 
      SHOW CREATE TABLE t2;

      returns

      +-------+-------------------------------------------------------------------------------------------------------------------------------------------------------------+
      		 
      | Table | Create Table                                                                                                                                                |
      		 
      +-------+-------------------------------------------------------------------------------------------------------------------------------------------------------------+
      		 
      | t2    | CREATE TABLE `t2` (
      		 
        `c1` decimal(14,4) DEFAULT NULL,
      		 
        `c2` decimal(14,4) DEFAULT NULL,
      		 
        `c3` double DEFAULT NULL
      		 
      ) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
      		 
      +-------+-------------------------------------------------------------------------------------------------------------------------------------------------------------+

      All three columns should be of the same data type.

      Attachments

        Activity

          bar Alexander Barkov added a comment - - edited

          Oops. There was a mistake in the script.
          The correct script is:

          DROP TABLE IF EXISTS t1,t2;
          		 
          CREATE TABLE t1 (c1 INT DEFAULT NULL);
          		 
          INSERT INTO t1 (c1) VALUES (1),(2),(3),(4);
          		 
          CREATE TABLE t2
          		 
          SELECT
          		 
            NULLIF(AVG(c1),0e0) AS c1,
          		 
            IF(AVG(c1)=0e0,NULL,AVG(c1)) AS c2,
          		 
            CASE WHEN AVG(c1)=0e0 THEN NULL ELSE AVG(c1) END AS c3
          		 
          FROM t1;
          		 
          SHOW CREATE TABLE t2;

          and it does return an expected result.

          bar Alexander Barkov added a comment - - edited Oops. There was a mistake in the script. The correct script is: DROP TABLE IF EXISTS t1,t2; CREATE TABLE t1 (c1 INT DEFAULT NULL); INSERT INTO t1 (c1) VALUES (1),(2),(3),(4); CREATE TABLE t2 SELECT NULLIF(AVG(c1),0e0) AS c1, IF(AVG(c1)=0e0,NULL,AVG(c1)) AS c2, CASE WHEN AVG(c1)=0e0 THEN NULL ELSE AVG(c1) END AS c3 FROM t1; SHOW CREATE TABLE t2; and it does return an expected result.

          People

            bar Alexander Barkov
            bar Alexander Barkov
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            Dates

              Created:
              Updated:
              Resolved:

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