Specifying Explicit Boundaries for Dimensions
By default, dimensions are 1-based — subscripts are numbered from 1.To specify explicit upper and lower bounds of the subscript values, use the following syntax:
'[' <lower>:<upper> ']'
By default, dimensions are 1-based — subscripts are numbered from 1.To specify explicit upper and lower bounds of the subscript values, use the following syntax:
'[' <lower>:<upper> ']'
A new dimension is added using a comma in the syntax.In this example we create a table with a two-dimensional array, with the lower bound of subscripts in both dimensions starting from zero:
CREATE TABLE SAMPLE_ARR2 (
ID INTEGER NOT NULL PRIMARY KEY,
ARR_INT INTEGER [0:3, 0:3]
);
The database employee.fdb
, found in the ../examples/empbuild
directory of any Firebird distribution package, contains a sample stored procedure showing some simple work with arrays:
SHOW_LANGS
, a procedure involving an arrayCREATE OR ALTER PROCEDURE SHOW_LANGS (
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
WHERE (JOB_CODE = :CODE)
AND (JOB_GRADE = :GRADE)
AND (JOB_COUNTRY = :CTY)
AND (LANGUAGE_REQ IS NOT NULL))
INTO :LANGUAGES;
IF (LANGUAGES = '') THEN
/* PRINTS 'NULL' INSTEAD OF BLANKS */
LANGUAGES = 'NULL';
I = I +1;
SUSPEND;
END
END
If the features described are enough for your tasks, you might consider using arrays in your projects.Currently, no improvements are planned to enhance support for arrays in Firebird.