Unity Android MySQL连接功能失败：索引超出了数组的范围

Question

I have a class to handle all of the database interactions between the client and database (MySQL) (I know and understand that I shouldn't allow direct access to a database)

public T getDatabaseValue<T>(string value, string query)
{
    try
    {
        connection = new MySqlConnection(connectionString);
        connection.Open();
        command = new MySqlCommand(query, connection);
        MySqlDataReader reader = command.ExecuteReader();
        if (reader.Read())
        {
            return (T)reader[value];
        }
        else
            return default(T);
    }
    catch (MySqlException SQLex)
    {
        Debug.Log("Database get failed (SQL Exception), query: " + query);
        Debug.Log("Exception Message: " + SQLex.Message);   
        return default(T);
    }
    catch (System.Exception ex)
    {
        Debug.Log("Database get failed (System Exception), query: " + query);
        Debug.Log("Exception Message: " + ex.Message);
        return default(T);
    }
}

This works flawlessly in the editor. When building and running on Android I get this error message via Monitor:

01-01 15:21:14.141: I/Unity(23761): (Filename: ./Runtime/Export/Debug.bindings.h Line: 43)
01-01 15:21:14.829: I/Unity(23761): Database get failed (System Exception), query: SELECT MAX(DT_Stamp) FROM tbl_Store;
01-01 15:21:14.829: I/Unity(23761):  
01-01 15:21:14.829: I/Unity(23761): (Filename: ./Runtime/Export/Debug.bindings.h Line: 43)
01-01 15:21:14.829: I/Unity(23761): Exception Message: Index was outside the bounds of the array.

I'm not using an array to store the contents of the reader, here is the line that calls this example (it happens for all database interactions, not just this one, and not just this database querying function):

    DateTime DB_Date = getDatabaseValue<DateTime>("MAX(DT_Stamp)", "SELECT MAX(DT_Stamp) FROM tbl_Store;");

Here's the contents of tbl_Store:

(Item_ID (int)), (Item_Name (varchar)), (Item_Price (float)), (In_Use (bit)), (DT_Stamp (datetime))

4 Hero Upgrade #1 100 1 2018-12-11 09:53:14 
5 Hero Upgrade #2 300 1 2018-12-11 09:53:14 
6 Hero Upgrade #3 700 1 2018-12-11 09:53:14 

I also tried it in a much more basic project to get the core error message returned by Android:

01-01 17:23:48.307: E/Unity(10476): IndexOutOfRangeException: Index was outside the bounds of the array. 
01-01 17:23:48.307: E/Unity(10476): at System.Diagnostics.TraceInternal.get_AppName () [0x0000e] in <ac210d81537245bc838518cc8e845861>:0 
01-01 17:23:48.307: E/Unity(10476): at System.Diagnostics.TraceInternal.TraceEvent (System.Diagnostics.TraceEventType eventType, System.Int32 id, System.String format, System.Object[] args) [0x0003d] in <ac210d81537245bc838518cc8e845861>:0 
01-01 17:23:48.307: E/Unity(10476): at System.Diagnostics.Trace.TraceError (System.String message) [0x00000] in <ac210d81537245bc838518cc8e845861>:0 
01-01 17:23:48.307: E/Unity(10476): at MySql.Data.MySqlClient.MySqlTrace.LogError (System.Int32 id, System.String msg) [0x00028] in <326e9aab93854e739606c3572c385a34>:0 
01-01 17:23:48.307: E/Unity(10476): at MySql.Data.MySqlClient.MySqlPool.TryToGetDriver () [0x00031] in <326e9aab93854e739606c3572c385a34>:0 
01-01 17:23:48.307: E/Unity(10476): at MySql.Data.MySqlClient.MySqlPool.GetConnection () [0x0001c] in <326e9aab93854e739606c3572c385a34>:0 
01-01 17:23:48.307: E/Unity(10476): at MySql.Data.MySqlClient.MySqlConnection.Open () [0x000f3] in <326e9aab93854e739606c3572c385a34>:0 
01-01 17:23:48.307: E/Unity(10476): at texttest1.Start () [0x00011] in <dd75ac8e3f854a97ac132dae6ec658fd>:0

I'm probably missing something really simple here but any help would be greatly appreciated!

Answer 1

I found the answer:

In order to get Android device to communicate externally you need to add I18N.dll and I18N.West.dll to your assets, this was the difference between it working in the Unity Editor and the Android APK.

Answer 2

There's nothing named that way ( MAX(DT_Stamp) ) in the result set. I would use AS name in your projection clause and reference it that way.