csv (Sink Mapper)

This output mapper extension allows you to convert Stream App events processed by the gdn SP to CSV message before publishing them. You can either use custom placeholder to map a custom CSV message or use pre-defined CSV format where event conversion takes place without extra configurations.

Syntax

CREATE SINK <NAME> WITH (map.type="csv", map.delimiter="<STRING>", map.header="<BOOL>", map.event.grouping.enabled="<BOOL>")

Query Parameters

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
delimiter	This parameter used to separate the output CSV data, when converting a Stream App event to CSV format,	,	STRING	Yes	No
header	This parameter specifies whether the CSV messages will be generated with header or not. If this parameter is set to true, message will be generated with header	false	BOOL	Yes	No
event.grouping.enabled	If this parameter is set to true, events are grouped via a line.separator when multiple events are received. It is required to specify a value for the System.lineSeparator() when the value for this parameter is true.	false	BOOL	Yes	No

Example 1

CREATE SINK BarStream WITH (type='inMemory', topic='{{symbol}}', map.type='csv') (symbol string, price float, volume long);

Above configuration will perform a default CSV output mapping, which will generate output as follows: symbol-price-volumegdn-55.6-100

If header is true and delimiter is "-", then the output will be as follows: symbol-price-volume

Example 2

CREATE SINK BarStream WITH (type='inMemory', topic='{{symbol}}', map.type='csv', map.header='true', map.delimiter='-', map.payload="symbol='0',price='2',volume='1'") (symbol string, price float,volume long);

Above configuration will perform a custom CSV mapping. Here, user can add custom place order in the @payload. The place order indicates that where the attribute name's value will be appear in the output message, The output will be produced output as follows: gdn,100,55.6

If header is true and delimiter is "-", then the output will be as follows: price-volume-symbol 55.6-100-gdn

If event grouping is enabled, then the output is as follows: price-volume-symbol 55.6-100-gdnSystem.lineSeparator() 55.6-100-IBMSystem.lineSeparator() 55.6-100-IFSSystem.lineSeparator()