| title | description | author | ms.author | ms.date | ms.service | ms.subservice | ms.topic | helpviewer_keywords | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Cursor Behaviors |
Cursor Behaviors |
markingmyname |
maghan |
10/24/2016 |
sql |
native-client |
reference |
|
[!INCLUDESQL Server Azure SQL Database Synapse Analytics PDW]
ODBC supports the ISO options for specifying the behavior of cursors by specifying their scrollability and sensitivity. These behaviors are specified by setting the SQL_ATTR_CURSOR_SCROLLABLE and SQL_ATTR_CURSOR_SENSITIVITY options on a call to SQLSetStmtAttr. The [!INCLUDEssNoVersion] Native Client ODBC driver implements these options by requesting server cursors with the following characteristics.
| Cursor behavior settings | Server cursor characteristics requested |
|---|---|
| SQL_SCROLLABLE and SQL_SENSITIVE | Keyset-driven cursor and version-based optimistic concurrency |
| SQL_SCROLLABLE and SQL_INSENSITIVE | Static cursor and read-only concurrency |
| SQL_SCROLLABLE and SQL_UNSPECIFIED | Static cursor and read-only concurrency |
| SQL_NONSCROLLABLE and SQL_SENSITIVE | Forward-only cursor and version-based optimistic concurrency |
| SQL_NONSCROLLABLE and SQL_INSENSITIVE | Default result set (forward-only, read-only) |
| SQL_NONSCROLLABLE and SQL_UNSPECIFIED | Default result set (forward-only, read-only) |
Version-based optimistic concurrency requires a timestamp column in the underlying table. If version-based optimistic concurrency control is requested on a table that does not have a timestamp column, the server uses values-based optimistic concurrency.
When SQL_ATTR_CURSOR_SCROLLABLE is set to SQL_SCROLLABLE, the cursor supports all the different values for the FetchOrientation parameter of SQLFetchScroll. When SQL_ATTR_CURSOR_SCROLLABLE is set to SQL_NONSCROLLABLE, the cursor only supports a FetchOrientation value of SQL_FETCH_NEXT.
When SQL_ATTR_CURSOR_SENSITIVITY is set to SQL_SENSITIVE, the cursor reflects data modifications made by the current user or committed by other users. When SQL_ATTR_CURSOR_SENSITIVITY is set to SQL_INSENSITIVE, the cursor does not reflect data modifications.