在PL/SQL Dev中依次打开：
Configure->Preferences->User Interface->Code Assistant->Coding Style
取消勾选“ Use original case if possible ”
关于该项在Manual中的解释如下：
Use original case if possible.
When this option is enabled, the Code Assistant will determine the case of the identifier from the source that is stored in the Oracle Dictionary if possible. This applies to all program units and their elements (parameters, types, and so on) and to view columns, and overrides the Coding Style preference described above. If the original case cannot be determined, the Coding Style will be applied.
You may want to disable this feature for performance reasons.