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  1. MariaDB Server
  2. MDEV-31137

UUID type is never used for user variables

Details

    • Bug
    • Status: Closed (View Workflow)
    • Major
    • Resolution: Not a Bug
    • 10.7(EOL), 10.8(EOL), 10.9(EOL), 10.10(EOL), 10.11
    • N/A
    • Variables

    Description

      The UUID() function correctly returns a value of type UUID. We can easily verify this with CREATE TABLE x SELECT UUID(); and SHOW CREATE TABLE x;.

      However, the value becomes VARCHAR if we try to assign it to a user variable:

      MariaDB [(none)]> SET @uuid := UUID();
      		 
      Query OK, 0 rows affected (0.000 sec)
      		 
       
      		 
      MariaDB [(none)]> SELECT VARIABLE_TYPE FROM information_schema.user_variables WHERE VARIABLE_NAME = 'uuid'
      		 
      ;
      		 
      +---------------+
      		 
      | VARIABLE_TYPE |
      		 
      +---------------+
      		 
      | VARCHAR       |
      		 
      +---------------+
      		 
      1 row in set (0.000 sec)

      The same happens if we try to cast the type explicitly:

      MariaDB [(none)]> SET @uuid := CAST(UUID() AS UUID);
      		 
      Query OK, 0 rows affected (0.000 sec)
      		 
       
      		 
      MariaDB [(none)]> SELECT VARIABLE_TYPE FROM information_schema.user_variables WHERE VARIABLE_NAME = 'uuid';
      		 
      +---------------+
      		 
      | VARIABLE_TYPE |
      		 
      +---------------+
      		 
      | VARCHAR       |
      		 
      +---------------+
      		 
      1 row in set (0.000 sec)

      This can lead to incorrect results:

      -- with dashes:
      		 
      MariaDB [(none)]> SELECT @uuid = 'fb025246-e48d-11ed-b010-56000464509c';
      		 
      +------------------------------------------------+
      		 
      | @uuid = 'fb025246-e48d-11ed-b010-56000464509c' |
      		 
      +------------------------------------------------+
      		 
      |                                              1 |
      		 
      +------------------------------------------------+
      		 
      1 row in set (0.000 sec)
      		 
       
      		 
      -- with no dashes:
      		 
      MariaDB [(none)]> SELECT @uuid = 'fb025246e48d11edb01056000464509c';
      		 
      +--------------------------------------------+
      		 
      | @uuid = 'fb025246e48d11edb01056000464509c' |
      		 
      +--------------------------------------------+
      		 
      |                                          0 |
      		 
      +--------------------------------------------+
      		 
      1 row in set (0.000 sec)

      Attachments

        Issue Links

          relates to

          Task - A task that needs to be done. MDEV-4958 Adding datatype UUID

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

          Activity

            People

              bar Alexander Barkov
              f_razzoli Federico Razzoli
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              Dates

                Created:
                Updated:
                Resolved:

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