System.Data.SqlClient.MetaType.GetMetaTypeFromValue C# (CSharp) Метод

        static internal MetaType GetMetaTypeFromValue(object value, bool inferLen = true, bool streamAllowed = true)
        {
            if (value == null)
            {
                throw ADP.InvalidDataType("null");
            }

            if (value is DBNull)
            {
                throw ADP.InvalidDataType(nameof(DBNull));
            }
            
            Type dataType = value.GetType();
            switch (Convert.GetTypeCode(value))
            {
                case TypeCode.Empty:
                    throw ADP.InvalidDataType(nameof(TypeCode.Empty));
                case TypeCode.Object:
                    
                    if (dataType == typeof (System.Byte[]))
                    {
                        if (!inferLen || ((byte[]) value).Length <= TdsEnums.TYPE_SIZE_LIMIT)
                        {
                            return MetaVarBinary;
                        }
                        else
                        {
                            return MetaImage;
                        }
                    }
                    if (dataType == typeof (System.Guid))
                    {
                        return s_metaUniqueId;
                    }
                    if (dataType == typeof (System.Object))
                    {
                        return s_metaVariant;
                    } 
                    // check sql types now
                    if (dataType == typeof (SqlBinary))
                        return MetaVarBinary;
                    if (dataType == typeof (SqlBoolean))
                        return s_metaBit;
                    if (dataType == typeof (SqlByte))
                        return s_metaTinyInt;
                    if (dataType == typeof (SqlBytes))
                        return MetaVarBinary;
                    if (dataType == typeof (SqlChars))
                        return MetaNVarChar;
                    if (dataType == typeof (SqlDateTime))
                        return s_metaDateTime;
                    if (dataType == typeof (SqlDouble))
                        return s_metaFloat;
                    if (dataType == typeof (SqlGuid))
                        return s_metaUniqueId;
                    if (dataType == typeof (SqlInt16))
                        return s_metaSmallInt;
                    if (dataType == typeof (SqlInt32))
                        return s_metaInt;
                    if (dataType == typeof (SqlInt64))
                        return s_metaBigInt;
                    if (dataType == typeof (SqlMoney))
                        return s_metaMoney;
                    if (dataType == typeof (SqlDecimal))
                        return MetaDecimal;
                    if (dataType == typeof (SqlSingle))
                        return s_metaReal;
                    if (dataType == typeof (SqlXml))
                        return MetaXml;
                    if (dataType == typeof (SqlString))
                    {
                        return ((inferLen && !((SqlString) value).IsNull)
                            ? PromoteStringType(((SqlString) value).Value)
                            : MetaNVarChar);
                    }

                    if (dataType == typeof (IEnumerable<DbDataRecord>) || dataType == typeof (DataTable))
                    {
                        return s_metaTable;
                    }

                    if (dataType == typeof (TimeSpan))
                    {
                        return MetaTime;
                    }

                    if (dataType == typeof (DateTimeOffset))
                    {
                        return MetaDateTimeOffset;
                    }
                    
                    if (streamAllowed)
                    {
                        // Derived from Stream ?
                        if (value is Stream)
                        {
                            return MetaVarBinary;
                        }
                        // Derived from TextReader ?
                        if (value is TextReader)
                        {
                            return MetaNVarChar;
                        }
                        // Derived from XmlReader ? 
                        if (value is XmlReader)
                        {
                            return MetaXml;
                        }
                    }
                    
                     throw ADP.UnknownDataType(dataType);                    
                case TypeCode.Boolean:
                    return s_metaBit;
                case TypeCode.Char:
                    throw ADP.InvalidDataType(nameof(TypeCode.Char));
                case TypeCode.SByte:
                    throw ADP.InvalidDataType(nameof(TypeCode.SByte));
                case TypeCode.Byte:
                    return s_metaTinyInt;
                case TypeCode.Int16:
                    return s_metaSmallInt;
                case TypeCode.UInt16:
                    throw ADP.InvalidDataType(nameof(TypeCode.UInt16));
                case TypeCode.Int32:
                    return s_metaInt;
                case TypeCode.UInt32:
                    throw ADP.InvalidDataType(nameof(TypeCode.UInt32));
                case TypeCode.Int64:
                    return s_metaBigInt;
                case TypeCode.UInt64:
                    throw ADP.InvalidDataType(nameof(TypeCode.UInt64));
                case TypeCode.Single:
                    return s_metaReal;
                case TypeCode.Double:
                    return s_metaFloat;
                case TypeCode.Decimal:
                    return MetaDecimal;
                case TypeCode.DateTime:
                    return s_metaDateTime;
                case TypeCode.String:
                    return (inferLen ? PromoteStringType((string) value) : MetaNVarChar);
                default:
                    throw ADP.UnknownDataType(dataType);
            }
        }

 private object ValidateBulkCopyVariant(object value)
 {
     switch (MetaType.GetMetaTypeFromValue(value).TDSType)
     {
     case 0xa5:
     case 0xa7:
     case 0xe7:
     case 0x7f:
     case 0x24:
     case 40:
     case 0x29:
     case 0x2a:
     case 0x2b:
     case 0x30:
     case 50:
     case 0x34:
     case 0x38:
     case 0x3b:
     case 60:
     case 0x3d:
     case 0x3e:
     case 0x6c:
         if (value is INullable)
         {
             return(MetaType.GetComValueFromSqlVariant(value));
         }
         return(value);
     }
     throw SQL.BulkLoadInvalidVariantValue();
 }