Basic Types Example

This page provides introduction to basic stream worker attribute types which are int, long, float, double, string, and object, 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

Below event is sent to PatientRegistrationInputStream,

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

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

Output

After processing, the event arriving at PatientRegistrationStream will be as follows:

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

Example

-- 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;