可滚动游标类型Scrollable Cursor Types

四种类型的可滚动游标为静态、动态、键集驱动和混合。The four types of scrollable cursors are static, dynamic, keyset-driven, and mixed. 静态游标只检测少量的更改,但要实现的成本相对较低。Static cursors detect few or no changes but are relatively cheap to implement. 动态游标检测所有更改,但实现成本高昂。Dynamic cursors detect all changes but are expensive to implement. 键集驱动游标和混合游标位于之间,检测大多数更改,但代价比动态游标更小。Keyset-driven and mixed cursors lie in between, detecting most changes but at less expense than dynamic cursors.

以下术语用于定义每种类型的可滚动游标的特征:The following terms are used to define the characteristics of each type of scrollable cursor:

  • 自己的更新、删除和插入。Own updates, deletes, and inserts. 通过调用 SQLBulkOperationsSQLSetPos 或者使用定位的 update 或 delete 语句,可以通过游标进行更新、删除和插入操作。Updates, deletes, and inserts made through the cursor, either with a call to SQLBulkOperations or SQLSetPos or with a positioned update or delete statement.

  • 其他更新、删除和插入。Other updates, deletes, and inserts. 不是由游标进行的更新、删除和插入操作,包括由同一事务中的其他操作所做的更改、通过其他事务进行的操作以及其他应用程序所做的更改。Updates, deletes, and inserts not made by the cursor, including those made by other operations in the same transaction, those made through other transactions, and those made by other applications.

  • 成员身份.Membership. 结果集中的行集。The set of rows in the result set.

  • 为了.Order. 游标返回行的顺序。The order in which rows are returned by the cursor.

  • 分隔.Values. 结果集中每一行的值。The values in each row in the result set.

有关如何更新、删除和插入数据的信息,请参阅 更新数据概述For information about how to update, delete, and insert data, see Updating Data Overview.

本部分包含以下主题。This section contains the following topics.