PLpgSQL不允许定义自己的异常-因此Orafce无法定义UTL_FILE.*异常.您应该查看orafce 源代码

PLpgSQL doesn't allow to define own exceptions - so Orafce cannot to define UTL_FILE.* exceptions. You should to look to orafce source code file.c to list of used exceptions:

代码使用宏CUSTOM_EXCEPTION

#define CUSTOM_EXCEPTION(msg, detail) \
    ereport(ERROR, \
        (errcode(ERRCODE_RAISE_EXCEPTION), \
         errmsg("%s", msg), \
         errdetail("%s", detail)))

在此列表中，您可以看到所有PostgreSQL异常.因此，使用的异常的名称为raise_exception，而异常的原因在SQLERRM变量中.因此，您的代码应类似于:

In this list you can see all PostgreSQL exceptions. So the name of used exception is raise_exception and the reason of exception is in SQLERRM variable. So your code should to look like:

WHEN RAISE_EXCEPTION THEN
  CASE SQLERRM
   WHEN 'UTL_FILE_INVALID_PATH' THEN
     PERFORM ...
   WHEN 'UTL_FILE_INVALID_MODE' THEN
     PERFORM ...
   ELSE 
     PERFORM ...
   END;