поддерживать запросы с дополнительными фильтрами, такими, как эти: SELECT AU.MAKE, AU.MODEL, AU.WEIGHT, AU.PRICE, AU.IN_STOCK FROM AUTOMOBILES AU WHERE (AU.MAKE = :MAKE OR :MAKE IS NULL) AND (AU.MODEL Firebird для подготовки, он должен быть преобразован в такую форму: SELECT AU.MAKE, AU.MODEL, AU.WEIGHT, 35 Руководство по языку SQL AU.PRICE, AU.IN_STOCK FROM AUTOMOBILES AU WHERE (AU.MAKE = ? OR null”. Эта последняя задача может быть решена путем приведения типов: SELECT AU.MAKE, AU.MODEL, AU.WEIGHT, AU.PRICE, AU.IN_STOCK FROM AUTOMOBILES AU WHERE (AU.MAKE = ? OR CAST(? AS TYPE OF COLUMN AU

use is e.g. select avg( nullif( Weight, -1 ) ) from FatPeople which will give you the average weight of the FatPeople population, without counting those with weight -1. (Remember that aggregate functions indicate “weight unknown” because you weren’t comfortable with NULLs. After reading this guide, you may feel brave enough to give the command: update FatPeople set Weight = nullif( Weight, -1 ) Now

and position <> 'Manager'; select name from wrestlers where region = 'Europe' and weight > all (select weight from shot_putters where region = 'Africa'); select id, name from input. Example select avg( nullif(Weight, -1) ) from FatPeople This will return the average weight of the persons listed in FatPeople, excluding those having a weight of -1, since AVG skips NULL data data. Presumably, -1 indicates “weight unknown” in this table. A plain AVG(Weight) would include the -1 weights, thus skewing the result. See also COALESCE(), DECODE(), IIF(), CASE Chapter 8. Built-in

AND position <> 'Manager'; SELECT name FROM wrestlers WHERE region = 'Europe' AND weight > ALL (SELECT weight FROM shot_putters WHERE region = 'Africa'); SELECT id, name FROM запрос вернёт среднее значение поля weight по таблице, за исключением строк, где он не указан (равен -1). Если бы не было этой функции простой оператор avg(weight) вернул бы некорректное значение значение */ SELECT AVG(NULLIF(weight, -1)) FROM cargo; См. также: COALESCE, CASE. Агрегатные функции Агрегатные функции выполняют вычисление на наборе значений

and position <> 'Manager'; select name from wrestlers where region = 'Europe' and weight > all (select weight from shot_putters where region = 'Africa'); select id, name from NULLIF Example select avg( nullif(Weight, -1) ) from FatPeople This will return the average weight of the persons listed in FatPeople, excluding those having a weight of -1, since AVG skips NULL data data. Presumably, -1 indicates “weight unknown” in this table. A plain AVG(Weight) would include the -1 weights, thus skewing the result. See also COALESCE(), DECODE(), IIF(), CASE 8.10. Special Functions

= 2) Chapter 3. Databases 6 Int32 Maximum type (e.g. ptype_batch_send = 3) Int32 Preference weight (e.g. 2) Server Int32 Operation code If operation equals op_accept: Int32 Protocol version

(Street = 'Main Street', Number = '888'); alter user benny tags (shoesize = '8', hair = 'blond', drop weight); alter current user set password 'SomethingEvenMoreSecretThanThis'; alter user dubya set inactive;

V.2.1.2 release, efforts have been made to improve the options, document them and to reduce the “weight” of installations, particularly for Windows Embedded deployments. Please refer to the later section

and position <> 'Manager'; select name from wrestlers where region = 'Europe' and weight > all (select weight from shot_putters where region = 'Africa'); select id, name from gleich dem zweiten. In diesem Fall wird NULL zurückgegeben. NULLIF-Beispiel select avg( nullif(Weight, -1) ) from FatPeople Dadurch wird das durchschnittliche Gewicht der in FatPeople aufgelisteten "NULL"-Daten überspringt. Vermutlich bedeutet -1 in dieser Tabelle “Gewicht unbekannt”. Ein einfaches AVG(Weight) würde die -1 Gewichte enthalten, wodurch das Ergebnis verzerrt wird. Siehe auch COALESCE(), DECODE()