NLS_LANG

After the new PL/SQL developer is installed, there is an error dialog "Database character set and client character set are different".

Because when my Oracle was installed, the character set parameter was set to UTF. Now the PL/SQL developer gets the NLS_LANG from system, which has a value of "GERMAN_GERMANY.WE8MSWIN1252". So this conflicts with the database setting and could cause data loss problem.

Solution: create NLS_LANG parameter in Enviroment Variables, set its value "American_America.AL32UTF8".