文档解释
ORA-24506: invalid attempt to change character set id on env handle
Cause: Attempts to change character set id after other handles have been allocated from the env handle
Action: Change character set id after creating environment handle but before allocating any handles from it.
ORA-24506 这是一个 Oracle 错误，这个错误指的是，在试图改变环境句柄的字符集标识时发生无效操作。
官方解释
ORA-24506: invalid attempt to change character set id on env handle
Cause: An attempt was made to change the character set ID of an environment handle that was previously initialized.
Action: Close the environment handle, re-initialize, and then change the character set ID.
常见案例
该错误通常发生在尝试使用环境句柄改变系统字符集时。当系统初始化时，字符集被固化到环境句柄中，因此无法改变。
一般处理方法及步骤
1. 关闭环境句柄。
2. 重新初始化环境句柄。
3. 重新更改字符集标识。
