. else ...поле Job изменилось... NULL в СУБД Firebird 12 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 полное имя человека с помощью COALESCE из первого, среднего и последнего имени, предполагая, что среднее имя может иметь значение NULL: select FirstName || coalesce(' ' || MiddleName, '')

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() BACKUP BIN_AND BIN_OR BIN_NOT BIN_SHL BIN_SHR BIN_XOR BLOCK BREAK CALLER CEIL CEILING CHAR_TO_UUID COALESCE 19 Руководство по языку SQL COLLATION COMMENT COMMON COS COSH COT DATA DATEADD DATEDIFF DECODE RDB$TYPES T ON R.RDB$RELATION_TYPE = T.RDB$TYPE WHERE T.RDB$FIELD_NAME = 'RDB$RELATION_TYPE' AND COALESCE (R.RDB$SYSTEM_FLAG, 0) = 0 ORDER BY 2, 1 GENERATED ALWAYS AS Добавлено: 2.1 Описание: Вместо

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 trucción “if (MiExpresion 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

est 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 « if (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, '')

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 14.1.1. The COALESCE function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 14. 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

.......................................................................................... 453 COALESCE ............................................................................................... например DATE '25.12.2016' Условные выражения Выражение CASE и встроенные функции COALESCE, NULLIF. Круглые скобки Пара скобок ( ... ) используются для группировки выражений. Операции внутри rdb$types t ON r.rdb$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

百度智能云文档 SQL手册 121 2.coalesce 3.if 4.ifnull 5.nullif CASE Description Description 功能：将表达式和多个可能的值进行比较，当匹配时返回相应的结果 返回类型：匹配后返回结果的类型 Example Example Keywords Keywords COALESCE Description Description -------------------------------------------------------------------------------+ case case coalesce coalesce(( expression expression,,value1 value1,,value2…… value2……,,valuen valuen)) Baidu 百度智能云文档 SQL手册 mysql>> select select coalesce coalesce((NULL NULL,, '1111' '1111',, '0000' '0000'));; ++--------------------------------+ --------------------------------+ || coalesce coalesce((NULL NULL,, '1111'

supports a variety of optimizations such as, • Dynamically Switch Join Strategies • Dynamically Coalesce Shuffle Partitions • Dynamically Handle Skew Joins In Kyuubi, we strongly recommended that you when the SortMerge Join transforms to BroadcastHash Join after applying the AQE rules. Dynamically Coalesce Shuffle Partitions Without this feature, Spark itself could be a small files maker sometimes, especially coalescePartitions.minPartitionNum to 1 in this case as Spark will try its best to but not guaranteed to coalesce partitions for output. How to set spark.sql.adaptive.coalescePartitions.initialPartitionNum? It

supports a variety of optimizations such as, • Dynamically Switch Join Strategies • Dynamically Coalesce Shuffle Partitions • Dynamically Handle Skew Joins In Kyuubi, we strongly recommended that you when the SortMerge Join transforms to BroadcastHash Join after applying the AQE rules. Dynamically Coalesce Shuffle Partitions Without this feature, Spark itself could be a small files maker sometimes, especially coalescePartitions.minPartitionNum to 1 in this case as Spark will try its best to but not guaranteed to coalesce partitions for output. How to set spark.sql.adaptive.coalescePartitions.initialPartitionNum? It

which supports a variety of optimizations such as, Dynamically Switch Join Strategies Dynamically Coalesce Shuffle Partitions Dynamically Handle Skew Joins In Kyuubi, we strongly recommended that you turn when the SortMerge Join transforms to BroadcastHash Join after applying the AQE rules. Dynamically Coalesce Shuffle Partitions Without this feature, Spark itself could be a small files maker sometimes, especially coalescePartitions.minPartitionNum to 1 in this case as Spark will try its best to but not guaranteed to coalesce partitions for output. How to set spark.sql.adaptive.coalescePartitions.initialPartitionNum? It