.............................................................................. 680 RDB$SECURITY_CLASSES ................................................................................................ Запрос с двумя подзапросами: SELECT p.fullname, (SELECT name FROM classes c WHERE c.id = p.class) AS class, (SELECT name FROM mentors m WHERE m.id = p.mentor) AS вместо подзапросов: SELECT p.fullname, c.name AS class, m.name AS mentor FROM pupils p JOIN classes c ON c.id = p.class JOIN mentors m ON m.id = p.mentor

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 740 RDB$SECURITY_CLASSES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 'Birne' similar to 'Birr%ne' -- false Notice how ‘%’ also matches the empty string. Character Classes A bunch of characters enclosed in brackets define a character class. A character in the string true 'Datte' similar to 'Dat[bcg-km-pwz]e' -- false Predefined Character Classes The following predefined character classes can also be used in a class definition: [:ALPHA:] Latin letters a..z and

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495 RDB$SECURITY_CLASSES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Notice how ‘%’ also matches the empty string. Chapter 4. Common Language Elements 68 Character Classes A bunch of characters enclosed in brackets define a character class. A character in the string true 'Datte' similar to 'Dat[bcg-km-pwz]e' -- false Predefined Character Classes The following predefined character classes can also be used in a class definition: [:ALPHA:] Latin letters a..z and

. . . . . . . . . . . . . . . . . . . . . . . . . . 666 Inhaltsverzeichnis 13 RDB$SECURITY_CLASSES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ) = current_date Eine Abfrage mit zwei Unterauswahlen: select p.fullname, (select name from classes c where c.id = p.class) as class, (select name from mentors m where m.id = p.mentor) as mentor von Subselects verwendet werden: select p.fullname, c.name as class, m.name as mentor join classes c on c.id = p.class from pupils p join mentors m on m.id = p.mentor Diese Abfrage verwendet ein

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 19.18. Show Security Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PROCedures PACKages ROLEs SYStem SEQuences SECURITY CLAsses SECCLAsses SCHEmas TABLEs TRIGgers USERS Secclasses SQL> SHOW SECCLAsses object_name; This command displays details about the security classes for a given object. The object_name passed Chapter 19. Isql Show commands 66 to the command need