Values

Values are typed data that can be manipulated, transferred, and stored. Values can be referred to by the attributes defined in definitions such as streams and tables.

Stream supports values of type STRING, INT (Integer), LONG, DOUBLE, FLOAT, BOOL (Boolean), and OBJECT.

Syntax

The syntax of each type and their example use as a constant value is as follows,

Attribute Type	Format	Example
int	+	123, -75, +95
long	+L	123000L, -750l, +154L
float	`(+)?('.'*)?(E(-	+)?+)?F`
double	`(+)?('.'*)?(E(-	+)?+)?D?`
bool	`(true	false)`
string	`'(;*!('	"

Time

Time is a special type of LONG value that denotes time using digits and their unit in the format (<digit>+ <unit>)+. At execution, the time gets converted into milliseconds and returns a LONG value.

Unit	Syntax
Year	year
Month	month
Week	week
Day	day
Hour	hour
Minutes	minute
Seconds	second
Milliseconds	millisecond

Example 1

1 hour and 25 minutes can by written as 1 hour and 25 minutes which is equal to the LONG value 5100000.

Example 2

This example provides introduction to basic stream worker attribute types and some key functions such as convert(), instanceOf...(), and cast().

In stream workers, other types such as list, map, etc, should be passed as an object into streams.

Input

The below event is sent to PatientRegistrationInputStream,

[1200098, 'Peter Johnson', 34, 194.3f, 69.6, #Fjoiu59%3hkjnknk$#nFT, true, 34]

Assume that the content of the photo (#Fjoiu59%3hkjnknk$#nFT) is binary.

Output

After processing, the event output at PatientRegistrationStream is:

[1200098, 'Peter Johnson', 34, 194.3, 69.6, #Fjoiu59%3hkjnknk$#nFT, false, true, 34]

Stream Worker Code

-- Defines `PatientRegistrationInputStream` with information in all primitive types.
CREATE STREAM PatientRegistrationInputStream (
                 seqNo long, name string, age int,
                 height float, weight double, photo object,
                 isEmployee bool, wardNo object);


-- Defines the resulting `PatientRegistrationStream` after processing.
CREATE STREAM PatientRegistrationStream (
                 seqNo long, name string, age int,
                 height double, weight double, photo object,
                 isPhotoString bool, isEmployee bool,
                 wardNo int);


@info(name = 'Type-processor')
INSERT INTO PatientRegistrationStream
SELECT seqNo, name, age,
-- `convert()` used to convert `float` type to `double`.
       convert(height, 'double') as height,

       weight, photo,
-- `instanceOfString()` checks if the photo is an instance of `string`.
       instanceOfString(photo) as isPhotoString,

       isEmployee,
-- `cast()` cast the value of wardNo to `int`.
       cast(wardNo, 'int') as wardNo
FROM PatientRegistrationInputStream;