igual... else ...El campo Trabajo ha cambiado... ## Substituyendo null por un valor ## La función COALESCE Firebird 1.5 tiene una función que puede convertir NULL a casi cualquier otra cosa. Esto te habilita construcción “if (MiExpresión is null) then”. La función se llama COALESCE y la puedes llamar así: COALESCE(Expr1, Expr2, Expr3, ...) COALESCE devuelve el primer valor no-NULL de la lista de argumentos. Si Si todas las expresiones son NULL, devuelve NULL. Así es como puedes usar COALESCE para construir el nombre completo de una persona desde el nombre, segundo nombre y primer apellido, asumiendo que algunos

поле Job осталось тем же... else ...поле Job изменилось... ## Замещение null значением ## Функция COALESCE В Firebird 1.5 есть функция, которая может конвертировать NULL во что-то еще. Это позволит вам конструкции «if (MyExpression is null) then». Функция называется COALESCE, и вы можете вызвать ее так: COALESCE(Expr1, Expr2, Expr3, ...) COALESCE возвращает первое не-NULL выражение из списка аргументов. Если сконструировать полное имя человека с помощью COALESCE из первого, среднего и последнего имени, предполагая, что среднее имя может иметь значение NULL: select FirstName || coalesce(' ' || MiddleName, '

resté le même... else ... le champ Job a changé... ## Substituer une valeur à NULL ## La fonction COALESCE Il existe une fonction dans Firebird 1.5 qui convertit NULL en quasiment tout ce que l'on veut (MyExpression is null) then ». Cette fonction s'appelle COALESCE et s'utilise comme suit : COALESCE(Expr1, Expr2, Expr3, ...) COALESCE retourne la première expression non-NULL dans la liste d'arguments Voici comment utiliser COALESCE pour écrire le nom complet d'une personne avec ses prénom, surnom et nom, en supposant que certains surnoms sont NULL: select Prenom || coalesce(' ' || Surnom

BIN_XOR() BIT_LENGTH() CAST() CEIL(), CEILING() CHAR_LENGTH(), CHARACTER_LENGTH() CHAR_TO_UUID() COALESCE() COS() COSH() COT() DATEADD() DATEDIFF() DECODE() EXP() EXTRACT() MILLISECOND WEEK FLOOR() BIN_OR BIN_NOT BIN_SHL BIN_SHR BIN_XOR BLOCK BREAK CALLER CEIL CEILING CHAR_TO_UUID COALESCE COLLATION COMMENT COMMON COS COSH COT DATA DATEADD DATEDIFF DECODE DELETING DIFFERENCE ON R.RDB$RELATION_TYPE = T.RDB$TYPE WHERE T.RDB$FIELD_NAME = 'RDB$RELATION_TYPE' AND COALESCE (R.RDB$SYSTEM_FLAG, 0) = 0 ORDER BY 2, 1 GENERATED ALWAYS AS Добавлено: 2.1 Описание: Вместо

Converting to and from NULL ..... 41 14.1. Substituting NULL with a value ..... 41 14.1.1. The COALESCE function ..... 41 14.1.2. Firebird 1.0: the *NVL functions ..... 41 14.2. Converting values Converting to and from NULL #### 14.1. Substituting NULL with a value ##### 14.1.1. The COALESCE function The COALESCE function in Firebird 1.5 and higher can convert NULL to most anything else. This enables (MyExpression is null) then” or similar constructions. The function signature is: COALESCE( Expr1, Expr2, Expr3, ...) COALESCE returns the value of the first non-NULL expression in the argument list. If all

Функции для работы с генераторами (последовательностями) 453 GEN_ID 453 Условные функции 453 COALESCE 453 decode 454 IIF 456 MAXVALUE 456 MINVALUE 457 NULLIF 458 регатные функции 458 AVG <value> например DATE '25.12.2016'| |Условные выражения|Выражение CASE и встроенные функции COALESCE, NULLIF.| |Круглые скобки|Пара скобок (...) используются для группировки выражений. Операции внутри t ON r.rdb$relation_type = t.rdb$type WHERE t.rdb$field_name = 'RDB$RELATION_TYPE' AND coalesce (r.rdb$system_flag, 0) = 0 Поле RDB$TYPE_NAME будет отображать PERSISTENT для обычной таблицы,

Manipulation Functions ...301 9.17. Conditional Expressions ...303 9.17.1. CASE ...303 9.17.2. COALESCE ...305 9.17.3. NULLIF ...305 9.17.4. GREATEST and LEAST ...306 9.18. Array Functions and Operators it's within a CASE arm that would never be entered at run time. ## 9.17.2. COALESCE COALESCE(value [, ...]) The COALESCE function returns the first of its arguments that is not null. Null is returned substitute a default value for null values when data is retrieved for display, for example: SELECT COALESCE(description, short_description, '(none)') ... This returns description if it is not null

Functions ... 231 9.16. Conditional Expressions ... 233 9.16.1. CASE ... 233 9.16.2. COALESCE ... 235 9.16.3. NULLIF ... 235 9.16.4. GREATEST and LEAST ... 235 9.17. Array Functions it's within a CASE arm that would never be entered at run time. ## 9.16.2. COALESCE COALESCE(value [, ...]) The COALESCE function returns the first of its arguments that is not null. Null is returned data is retrieved for display, for example: SELECT COALESCE(description, short_description, '(none)') ... Like a CASE expression, COALESCE only evaluates the arguments that are needed to determine

Manipulation Functions ... 250 9.17. Conditional Expressions ... 252 9.17.1. CASE ... 252 9.17.2. COALESCE ... 254 9.17.3. NULLIF ... 254 9.17.4. GREATEST and LEAST ... 254 9.18. Array Functions and Operators it's within a CASE arm that would never be entered at run time. ## 9.17.2. COALESCE COALESCE(value [, ...]) The COALESCE function returns the first of its arguments that is not null. Null is returned substitute a default value for null values when data is retrieved for display, for example: SELECT COALESCE(description, short_description, '(none)') ... This returns description if it is not null

Manipulation Functions.....258 9.17. Conditional Expressions.....261 9.17.1. CASE.....261 9.17.2. COALESCE.....263 9.17.3. NULLIF.....263 9.17.4. GREATEST and LEAST.....263 9.18. Array Functions and it's within a CASE arm that would never be entered at run time. ##### 9.17.2. COALESCE COALESCE(value [, ...]) The COALESCE function returns the first of its arguments that is not null. Null is returned substitute a default value for null values when data is retrieved for display, for example: SELECT COALESCE(description, short_description, '(none)' ) ... This returns description if it is not null