MySqlCommandBuilder.DeriveParameters: Specified cast is not valid

Question

I am using MySql.Data version 8.0.22 on IIS/Windows to try and connect to MariaDB 10.4.12 (Linux). I am trying to use MySqlCommandBuilder.DeriveParameters to fetch parameter information:

        cmd.CommandText = "Mail_SaveEvent";
        cmd.CommandType = CommandType.StoredProcedure;
        MySqlCommandBuilder.DeriveParameters(cmd);

My stored proc/routine has the following parameters:

CREATE PROCEDURE shopmail_test.Mail_SaveEvent(
    IN inEventTypeID int,
    IN inEventDate datetime,
    IN inEventServer int,
    IN inEventTitle varchar(250),
    IN inEventText text,
    IN inEventMerchantID int,
    IN inEventAuditText text,
    IN inEventID int)
  SQL SECURITY INVOKER
  MODIFIES SQL DATA
BEGIN

I thought this might be a collation issue (I am using utf8 with utf8_unicode_ci collation), so I commented out all of the text parameters and even removed most of the logic from the body of the routine but I am still getting the following error:

12/4/2020 11:20 AM][Production  ]:          Specified cast is not valid.
[12/4/2020 11:20 AM][Production  ]:            at MySql.Data.MySqlClient.MySqlCommandBuilder.DeriveParameters(MySqlCommand command)

What's interesting is that if I try and hit this same schema/routine on MariaDB 10.4.17 hosted on a Windows box that the command is populated without any errors.

This is driving me nuts! Has anyone experienced this and found out how to fix it?

Answer 1

This is probably a bug in MySql.Data (although I don't yet see a relevant report at https://bugs.mysql.com/). You could report it there, and hope that Oracle fixes it in a future version.

Alternatively, switch to MySqlConnector (disclaimer: lead author), which fixes a lot of MySql.Data bugs and has great compatibility with MariaDB.