........................................................................................... 311 DELETE ................................................................................................ конструкцию в операторе. Например, предложение WHERE в операторе SELECT и в ряде других операторов (UPDATE, DELETE) задаёт условия поиска данных в таблице (таблицах), подлежащих выборке, изменению, удалению. Предложение Удаление теневой копии. Доступно в: DSQL, ESQL. Синтаксис: DROP SHADOW number [{PRESERVE | DELETE} FILE]; Таблица 4.4. Параметры оператора DROP SHADOW Параметр Описание number

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 6.5. DELETE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . the WHERE clause in a SELECT statement and in some other data manipulation statements (UPDATE, DELETE) specifies criteria for searching one or more tables for the rows that are to be selected, updated statement you can: • rename the domain • change the data type • delete the current default value • set a new default value • delete an existing CHECK constraint • add a new CHECK constraint Short

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 6.5. DELETE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . the WHERE clause in a SELECT statement and in some other data manipulation statements (UPDATE, DELETE) specifies criteria for searching one or more tables for the rows that are to be selected, updated definition language subset of Firebird’s SQL language. DDL statements are used to create, modify and delete database objects that have been created by users. When a DDL statement is committed, the metadata

TRIGGER VIEW CREATE VIEW ALTER VIEW CREATE OR ALTER VIEW RECREATE VIEW 7. Операторы DML DELETE Использование COLLATE для столбцов с текстовым BLOB ORDER BY PLAN Использование алиаса делает UPPER(NAME); SELECT * FROM PERSONS WHERE UPPER(NAME) STARTING WITH 'VAN'; DELETE FROM PERSONS WHERE UPPER(NAME) = 'BROWN'; DELETE FROM PERSONS WHERE UPPER(NAME) = 'BROWN' AND AGE > 65; CREATE DESCENDING TEMPORARY TABLE name (column_def [, column_def | table_constraint ...]) [ON COMMIT {DELETE | PRESERVE} ROWS] • ON COMMIT DELETE ROWS создаёт a GTT транзакционного уровня (по умолчанию), ON COMMIT PRESERVE

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317 6.5. DELETE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . WHERE in einer SELECT-Anweisung und in einigen anderen Datenmanipulationsanweisungen (UPDATE, DELETE) Kriterien zum Durchsuchen einer oder mehrerer Tabellen nach den Zeilen, die ausgewählt, aktualisiert eines Schattens aus der aktuellen Datenbank Verfügbar in DSQL, ESQL Syntax DROP SHADOW sh_num [{DELETE | PRESERVE} FILE] Tabelle 23. DROP SHADOW-Anweisungsparameter Parameter Beschreibung sh_num Schattennummer

modify the user record. -85 335544756 error_deleting_sec_record An error occurred while attempting to delete the user record. -85 335544757 error_updating_sec_db An error occurred while updating the security check_cnstrnt_update Cannot update constraints (RDB$CHECK_CONSTRAINTS). -294 335544536 check_cnstrnt_del Cannot delete CHECK constraint entry (RDB$CHECK_CONSTRAINTS) -295 335544545 rel_cnstrnt_update Cannot update constraints already in use -616 335544530 primary_key_ref Cannot delete PRIMARY KEY being used in FOREIGN KEY definition. -616 335544539 integ_index_del Cannot delete index used by an Integrity Constraint -616 335544540

the user record. -85 335544756 error_deleting_sec_record An error occurred while attempting to delete the user record. -85 335544757 error_updating_sec_db An error occurred while updating the security check_cnstrnt_update Cannot update constraints (RDB$CHECK_CONSTRAINTS). -294 335544536 check_cnstrnt_del Cannot delete CHECK constraint entry (RDB$CHECK_CONSTRAINTS) -295 335544545 rel_cnstrnt_update Cannot update already in use -616 335544530 primary_key_ref Cannot delete PRIMARY KEY being used in FOREIGN KEY definition. -616 335544539 integ_index_del Cannot delete index used by an Integrity Constraint -616 335544540

modify the user record. -85 335544756 error_deleting_sec_record An error occurred while attempting to delete the user record. -85 335544757 error_updating_sec_db An error occurred while updating the security check_cnstrnt_update Cannot update constraints (RDB$CHECK_CONSTRAINTS). -294 335544536 check_cnstrnt_del Cannot delete CHECK constraint entry (RDB$CHECK_CONSTRAINTS) -295 335544545 rel_cnstrnt_update Cannot update constraints already in use -616 335544530 primary_key_ref Cannot delete PRIMARY KEY being used in FOREIGN KEY definition. -616 335544539 integ_index_del Cannot delete index used by an Integrity Constraint -616 335544540

both of which allow you to : ◦ Display user details. ◦ Amend user details. ◦ Add new users. ◦ Delete existing users. • Using gsec to administer a remote security database. • Some caveats, gotchas adding a new user: add [ ... ] deleting a current user: delete displaying all users: display displaying one user: display add command. Alternatively, you may add a user then modify it to fill in the missing details. -delete This command removes the named user from the database. All details of the user are removed

Стандартные операторы Стандартными операторами, имеющимися в обоих СУБД, являются SELECT, INSERT, UPDATE и DELETE. СУБД Firebird и MS SQL поддерживают их, но в СУБД MS SQL есть несколько нестандартных расши- рений оператора DELETE. СУБД MS SQL так- же поддерживает оператор TRUNCATE TABLE, который более эффективен (но и опаснее), чем оператор DELETE. (СУБД MS SQL также поддерживает синтаксис оператора DELETE, в котором ..или... */ DELETE FROM my_table /* Синтаксис Firebird. */ DELETE FROM my_table Самая большая угроза - действовать «методом тыка». Больше всего данных было утеряно ко- мандами "delete from xxx" и последующей