. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357 7.7.3. DECLARE VARIABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . characters (252 bytes). Two types of names are valid as identifiers: regular names, similar to variable names in regular programming languages, and delimited names that are specific to SQL. To be valid a BLOB segment is limited to 64K. The maximum size of a BLOB field is 4 GB A data type of variable size for storing large amounts of data, such as images, text, digital sounds. The basic structural

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 7.6.3. DECLARE VARIABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . names are valid as Chapter 2. SQL Language Structure 19 identifiers: regular names, similar to variable names in regular programming languages, and delimited names that are specific to SQL. To be valid segment is limited to 64K. The maximum size of a BLOB field is 4 GB A data type of a dynamically variable size for storing large amounts of data, such as images, text, digital sounds. The basic structural

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344 7.7.2. DECLARE VARIABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3 6. PSQL-Deklaration mit Startwert DECLARE VARIABLE VAR1 BOOLEAN = TRUE; 7. Gültige Syntax, aber wie bei einem Vergleich mit NULL, wird nie ein Datensatz CODE VARCHAR(5), GRADE SMALLINT, CTY VARCHAR(15)) RETURNS (LANGUAGES VARCHAR(15)) AS DECLARE VARIABLE I INTEGER; BEGIN I = 1; WHILE (I <= 5) DO BEGIN SELECT LANGUAGE_REQ[:I] FROM JOB

.................................. 346 Руководство по языку SQL СУБД Firebird 3.0 13 DECLARE VARIABLE ............................................................................................ 346 использующего строковые литералы. EXECUTE BLOCK RETURNS ( RDB$TRIGGER_NAME CHAR(31) ) AS DECLARE VARIABLE S VARCHAR(8191); BEGIN S = 'SELECT RDB$TRIGGER_NAME FROM RDB$TRIGGERS WHERE RDB$RELATION_NAME 3 -- PSQL объявления с начальным значением DECLARE VARIABLE VAR1 BOOLEAN = TRUE; -- Допустимый синтаксис, но как и сравнение -- с NULL, никогда не вернёт

Блок BEGIN ... END может быть пустым BREAK CLOSE CURSOR DECLARE DECLARE ... CURSOR DECLARE [VARIABLE] с инициализацией DECLARE с DOMAIN вместо типа данных TYPE OF COLUMN в объявлении переменных и colname SET DEFAULT 83 Руководство по языку SQL ::= literal-value | context-variable | NULL Пример: ALTER TABLE CUSTOMERS ALTER ENTEREDBY SET DEFAULT CURRENT_USER Совет Если Вы ON CONNECT POSITION 10 AS DECLARE VARIABLE REMOTE_PROTOCOL VARCHAR(8); DECLARE VARIABLE APP_NAME VARCHAR(253); DECLARE VARIABLE SERVER_PID INTEGER; DECLARE VARIABLE PC_USER_PID INTEGER; BEGIN SELECT

................................................................................ 1 The FIREBIRD Variable ............................................................................................... 1.2 Release Notes, in Changes to the Firebird API and ODS. The FIREBIRD Variable FIREBIRD is an optional environment variable that provides a system-level pointer to the root directory of the Firebird installation. If it exists, it is available everywhere in the scope for which the variable was defined. The FIREBIRD variable is NOT removed by scripted uninstalls and it is not updated by the installer scripts

PROCEDURE my_procedure AS DECLARE @my_variable int SET @my_variable = 5 /* Firebird */ CREATE PROCEDURE my_procedure AS DECLARE VARIABLE my_variable int; BEGIN my_variable = 5; END В обоих СУБД параметры /* Это процедура-выборка. */ CREATE PROCEDURE list_states RETURNS (state varchar(64)) AS DECLARE VARIABLE short_state CHAR(2); BEGIN FOR SELECT state FROM authors INTO :short_state DO BEGIN EXECUTE NEXT FROM my_cursor END CLOSE my_cursor DEALLOCATE my_cursor /* Синтакс Firebird. */ DECLARE VARIABLE au_lname VARCHAR(40); ... FOR SELECT au_lname FROM authors ORDER BY au_lname INTO :au_lname

unknown”, it is the logical default state for any field or variable that has been created but not provided with a value: • If you declare a variable in a stored procedure or trigger, its value is undefined in the section Altering populated tables. 2.2. Testing for NULL If you want to know whether a variable, field or other expression is NULL, use the following syntax: IS [NOT] NULL Examples: NULL always return true or false; they never return NULL. 2.3. Assigning NULL Setting a field or variable to NULL is done with the ‘=’ operator, just like assigning values. You can also include NULL in

en un entorno gráfico, abra una ventana de comandos. 2. Primero, asegúrese de tener definida una variable llamada CVS_RSH con el valor “ssh” (o como se llame su cliente SSH). Cómo hacer esto depende de escriba set CVS_RSH=ssh. En Linux/bash: export CVS_RSH=ssh. Ud. puede querer hacer permanente esta variable de entorno, de tal manera que pueda saltear este paso en el futuro. Cómo hacer esto depende de su Firebird. Cómo configurar el entorno para la construcción Los scripts de construcción necesitan una variable de entorno JAVA_HOME apuntando al directorio de instalación de Java 2. • En Windows, típicamente

....................................................................... 8 Colocando un campo o variable a NULL ........................................................................................ operaciones o comparaciones. Cuando veas NULL en las expresiones siguientes, léelas como “un campo, variable u otra expresión que resuelve en NULL”. Guía de NULL en Firebird 4 Expresiones que devuelven se resuelven todas con NULL: • 0 * NULL • NULL >= '' • '' <= NULL • A = A (con A como un campo o variable NULL) Demasiado para la coherencia. NULL en funciones agregadas En funciones agregadas como COUNT