文档解释
ORA-21520: database server driver not installed
Cause: User attempted to access a database server through an object-mode OCI environment but the necessary driver for supporting such access to the database server is not installed or linked in.
Action: Check if the driver corresponding to the database server has been installed/linked in and entered in the server driver table.
ORA-21520是Oracle数据库服务器中的一种错误，它表明数据库驱动程序没有被正确安装。
官方解释
ORA-21520: database server driver not installed
Cause: The database server failed to install the requested driver.
Action: Reinstall the driver or contact Oracle Support Services.
常见案例
该错误通常发生在安装新的Oracle数据库驱动程序时，但没有成功完成安装。
一般处理方法及步骤
1.重新下载Oracle驱动程序，确保是最新的可用版本。
2.按照Oracle数据库文档中指定的步骤仔细安装驱动程序。
3.确保安装步骤结束后，完成所有需向正确配置的步骤并重启服务器。
