Retrieving data from Sqlite database using Mono.Data.Sqlite

I have an example code, it is minimal so you can just copy and paste it and try. (You also need Mono.Data.Sqlite.dll, System.Data.dll and sqlite3.dll)

The errors I receive are given as comments.

 using UnityEngine;
 using Mono.Data.Sqlite;
 
 public class Example : MonoBehaviour
 {
     void Start ()
     {
         using (var dbcon = new SqliteConnection("URI=file:example.db,version=3"))
         {
             dbcon.Open();
             using (var dbcmd = dbcon.CreateCommand())
             {
                 dbcmd.CommandText = "CREATE TABLE Example (value REAL);";
                 dbcmd.ExecuteNonQuery();
             }
 
             using (var dbcmd = dbcon.CreateCommand())
             {
                 dbcmd.CommandText = "INSERT INTO Example (value) VALUES (3.141592653589793);";
                 dbcmd.ExecuteNonQuery();
             }
 
             using (var dbcmd = dbcon.CreateCommand())
             {
                 dbcmd.CommandText = "SELECT * FROM Example";
                 using (var reader = dbcmd.ExecuteReader())
                 {
                     if (reader.Read())
                     {
                         Debug.Log(reader.GetDataTypeName(0)); // REAL   -- OK
                         Debug.Log(reader.GetName(0)); // value   -- OK
                         Debug.Log(reader.GetFloat(0)); // 3.141593   -- seems OK
                         Debug.Log(reader.GetDouble(0)); // 3.14159265358979   -- OK
                         Debug.Log(reader.GetValue(0).GetType()); // System.Single   -- Why?
                         Debug.Log(reader.GetFieldType(0)); // System.Single   -- Why?
                         Debug.Log((float)reader.GetValue(0)); // 3.141593   -- OK
                         Debug.Log((double)(float)reader.GetValue(0)); // 3.14159274101257   -- also OK
                         Debug.Log((double)reader.GetValue(0)); // InvalidCastException   -- Why?
                     }
                 }
             }
         }
     }
 }

The problem is, GetFieldType() and GetValue().GetType() both return System.Single (aka float). GetValue() return as a float type. However, it is certain that there is a double value in there which I can't get with GetValue().

I am trying to write a method that takes the reader, and converts it to List<Dictionary<string,object>> but GetValue() returning a float is an issue for me. Is this a Unity bug? or Mono bug? on not a bug at all?