The `TaosConnection` class contains both an implementation of the PEP249 Connection interface (e.g., the `cursor()` method and the `close()` method) and many extensions (e.g., the `execute()`, `query()`, `schemaless_insert()`, and `subscribe()` methods).
The queried results can only be fetched once. For example, only one of `fetch_all()` and `fetch_all_into_dict()` can be used in the example above. Repeated fetches will result in an empty list.
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##### Use of TaosResult class
In the above example of using the `TaosConnection` class, we have shown two ways to get the result of a query: `fetch_all()` and `fetch_all_into_dict()`. In addition, `TaosResult` also provides methods to iterate through the result set by rows (`rows_iter`) or by data blocks (`blocks_iter`). Using these two methods will be more efficient in scenarios where the query has a large amount of data.
The `TaosConnection` class and the `TaosResult` class already implement all the functionality of the native interface. If you are familiar with the interfaces in the PEP249 specification, you can also use the methods provided by the `TaosCursor` class.
The TaosCursor class uses native connections for write and query operations. In a client-side multi-threaded scenario, this cursor instance must remain thread exclusive and cannot be shared across threads for use, otherwise, it will result in errors in the returned results.
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</TabItem>
<TabItem value="rest" label="REST connection">
##### Use of TaosRestCursor class
The `TaosRestCursor` class is an implementation of the PEP249 Cursor interface.
- `cursor.execute`: Used to execute arbitrary SQL statements.
- `cursor.rowcount` : For write operations, returns the number of successful rows written. For query operations, returns the number of rows in the result set.
- `cursor.description` : Returns the description of the field. Please refer to [TaosRestCursor](https://docs.taosdata.com/api/taospy/taosrest/cursor.html) for the specific format of the description information.
##### Use of the RestClient class
The `RestClient` class is a direct wrapper for the [REST API](/reference/rest-api). It contains only a `sql()` method for executing arbitrary SQL statements and returning the result.