| ADO | ADO .NET |
| Business Model | Connection-oriented Models used mostly | Disconnected models are used:Message-like Models. |
| Disconnected Access | Provided by Record set | Provided by Data Adapter and Data set |
| XML Support | Limited | Robust Support |
| Data Passing | ADO objects communicate in binary mode. | ADO.NET uses XML for passing the data. |
| Design-time support | Derives information about data implicitly at run time, based on metadata that is often expensive to obtain. | Leverages known metadata at design time in order to provide better run-time performance and more consistent run-time behavior. |
| Control of data access behaviors | Includes implicit behaviors that can not always be required in an application and that can therefore limit performance. | Provides well-defined, factored components with predictable behavior, performance, and semantics. |
| Connection Model | Client application needs to be connected always to data-server while working on the data, unless using client-side cursors or a disconnected Record set | Client disconnected as soon as the data is processed. DataSet is disconnected at all times. |
ADO Versus ADO.NET Data Types
| Code | Symbol |
| adEmpty | null |
| adBoolean | Int16 |
| adTinyInt | SByte |
| adSmallInt | Int16 |
| adInteger | Int32 |
| adBigInt | Int64 |
| adUnsignedTinyInt | promoted to Int16 |
| adUnsignedSmallInt | promoted to Int32 |
| adUnsignedInt | promoted to Int64 |
| adUnsignedBigInt | promoted to Decimal |
| adSingle | Single |
| adDouble | Double |
| adCurrency | Decimal |
| adDecimal | Decimal |
| adNumeric | Decimal |
| adDate | DateTime |
| adDBDate | DateTime |
| adDBTime | DateTime |
| adDBTimeStamp | DateTime |
| adFileTime | DateTime |
| adGUID | Guid |
| adError | ExternalException |
| adIUnknown | object |
| adIDispatch | object |
| adVariant | object |
| adPropVariant | object |
| adBinary | byte[] |
| adChar | string |
| adWChar | string |
| adBSTR | string |
| adChapter | not supported |
| adUserDefined | not supported |
