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  1. MariaDB Server
  2. MDEV-32816

Make "show collations" data not-nullable

Details

    • Bug
    • Status: Closed (View Workflow)
    • Minor
    • Resolution: Duplicate
    • None
    • N/A
    • Protocol
    • None

    Description

      MariaDb returns some nulls as collation info.
      That crashes the .Net MySql driver and Oracle os not willing to fix their driver.
      –
      On connect, the driver tries to load collations IDs and cast them to
      integers.
      However collation is nullable and there are some null-collations, for
      example:

      +--------------------------------+----------+------+---------+----------+---------+
      		 
      | Collation                      | Charset  | Id   | Default | Compiled
      		 
      | Sortlen |
      		 
      +--------------------------------+----------+------+---------+----------+---------+
      		 
       
      		 
      | uca1400_ai_ci                  | NULL     | NULL | NULL    | Yes     
      |       8 |
      		 
      | uca1400_ai_cs                  | NULL     | NULL | NULL    | Yes     
      |       8 |
      		 
      | uca1400_as_ci                  | NULL     | NULL | NULL    | Yes     
      |       8 |
      		 
      | uca1400_as_cs                  | NULL     | NULL | NULL    | Yes     
      |       8 |

      So the driver fails to connect the database:
      InvalidCast_FromDBNull: Object cannot be cast from DBNull to other
      types.

      Driver has the following code:

                      MySqlCommand mySqlCommand = new MySqlCommand("SHOW COLLATION",
      		 
      connection);
      		 
                      try
      		 
                      {
      		 
                              using MySqlDataReader mySqlDataReader =
      		 
      mySqlCommand.ExecuteReader();
      		 
                              CharacterSets = new Dictionary<int, string>();
      		 
                              while (mySqlDataReader.Read())
      		 
                              {
      		 
                                      CharacterSets[Convert.ToInt32(mySqlDataReader["id"],
      		 
      NumberFormatInfo.InvariantInfo)] =
      		 
      mySqlDataReader.GetString(mySqlDataReader.GetOrdinal("charset"));
      		 
                              }
      		 
                      }
      		 
                      catch (Exception ex)
      		 
                      {
      		 
                              MySqlTrace.LogError(ThreadID, ex.Message);
      		 
                              throw;
      		 
                      }

      –
      See e.g.: https://bugs.mysql.com/bug.php?id=109331

      Attachments

        Issue Links

          duplicates

          Bug - A problem which impairs or prevents the functions of the product. MDEV-31608 MySQL.Data can not connect to MariaDB 11 due a collations with a NULL id.

          • Blocker - Blocks development and/or testing work, production could not run.
          • Closed
          is caused by

          Task - A task that needs to be done. MDEV-27009 Add UCA-14.0.0 collations

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

          Activity

            Ascending order - Click to sort in descending order
            danblack Daniel Black added a comment -

            Is there a reason the https://github.com/mysql-net/MySqlConnector and MariaDB Connector/J are unacceptable solutions?

            danblack Daniel Black added a comment - Is there a reason the https://github.com/mysql-net/MySqlConnector and MariaDB Connector/J are unacceptable solutions?
            wlad Vladislav Vaintroub added a comment - - edited

            danblack, I do not think we can force anyone to MySqlConnector no matter how good it is, the Oracle's connector remains slightly more popular.
            It is not a drop-in, and people may depend on other open source or closed source software, which happened to use Oracle's connector
            Also, as we promised client compatibity, I think we should try to keep this promise

            I tried to collect some links on the internet for this issue , it is in MDEV-31608 . We broke OnlyOffice, PowerBI, Toad, and some other stuff with NULL collation ids (something that nobody uses, and something that could be put into a dedicated table).

            wlad Vladislav Vaintroub added a comment - - edited danblack , I do not think we can force anyone to MySqlConnector no matter how good it is, the Oracle's connector remains slightly more popular. It is not a drop-in, and people may depend on other open source or closed source software, which happened to use Oracle's connector Also, as we promised client compatibity, I think we should try to keep this promise I tried to collect some links on the internet for this issue , it is in MDEV-31608 . We broke OnlyOffice, PowerBI, Toad, and some other stuff with NULL collation ids (something that nobody uses, and something that could be put into a dedicated table).

            People

              Unassigned Unassigned
              thorium Tuomas Hietanen
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              Dates

                Created:
                Updated:
                Resolved:

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