keyvalue (Sink Mapper)

The Event to Key-Value Map output mapper extension allows you to convert Stream App events processed by gdn SP to key-value map events before publishing them. You can either use pre-defined keys where conversion takes place without extra configurations, or use custom keys with which the messages can be published.

Syntax

CREATE SINK <NAME> WITH (map.type="keyvalue")

Example 1

CREATE SINK FooStream WITH (type='inMemory', topic='stock', map.type='keyvalue') (symbol string, price float, volume long);

This query performs a default Key-Value output mapping. The expected output is something similar to the following: symbol:gdn price : 55.6f volume: 100L

Example 2

CREATE SINK FooStream WITH (type='inMemory', topic='stock', map.type='keyvalue', map.payload="a='symbol',b='price',c='volume'") (symbol string, price float, volume long);

This query performs a custom Key-Value output mapping where values are passed as objects. Values for symbol, price, and volume attributes are published with the keys a, b and c respectively. The expected output is a map similar to the following: a:gdn b : 55.6f c: 100L

Example 3

CREATE SINK FooStream WITH (type='inMemory', topic='stock', map.type='keyvalue', map.payload="a='{{symbol}} is here',b='`price`',c='volume'") (symbol string, price float, volume long);

This query performs a custom Key-Value output mapping where the values of the a and b attributes are strings and c is object. The expected output should be a Map similar to the following: a:gdn is here b : price c: 100L