一般而言，设备句柄由具体设备驱动程序的名称决定。
Generally speaking, the device handle is determined by the name of a particular device driver.
当使用 DBI->connect 语句（语法如下）来创建一个数据库句柄 时，DBI 模块会自动加载 DBD::DB2 驱动程序。
The DBI module automatically loads the DBD::DB2 driver when you create a database handle using the DBI->connect statement with the following syntax
为了能够使得驱动程序跟踪这些实例，系统会在实例创建完成后在每个驱动消息中带有一个驱动实例句柄。
To help the driver keep track of the instances, the system sends a driver instance handle with each driver message after the instance has been created.
应用推荐