Help Center/ Data Lake Insight/ Flink SQL Syntax Reference/ Flink Opensource SQL 1.10 Syntax Reference/ Data Definition Language (DDL)/ Creating a Result Table/ Upsert Kafka Result Table
Updated on 2024-09-29 GMT+08:00
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Upsert Kafka Result Table

Function

DLI exports the output data of the Flink job to Kafka in upsert mode.

Apache Kafka is a fast, scalable, and fault-tolerant distributed message publishing and subscription system. It delivers high throughput and built-in partitions and provides data replicas and fault tolerance. Apache Kafka is applicable to scenarios of handling massive messages.

Prerequisites

Kafka is an offline cluster. You have built an enhanced datasource connection to connect Flink jobs to Kafka. You have set security group rules as required.

Precautions

SASL_SSL cannot be enabled for the interconnected Kafka cluster.

Syntax

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create table kafkaSource(
  attr_name attr_type 
  (',' attr_name attr_type)* 
  (','PRIMARY KEY (attr_name, ...) NOT ENFORCED)
)
with (
  'connector.type' = 'upsert-kafka',
  'connector.version' = '',
  'connector.topic' = '',
  'connector.properties.bootstrap.servers' = '',
   'format.type' = ''
);

Parameters

Table 1 Parameter description

Parameter

Mandatory

Description

connector.type

Yes

Connector type. Set this parameter to upsert-kafka.

connector.version

No

Kafka version. The value can only be 0.11.

format.type

Yes

Data serialization format. The value can be csv, json, or avro.

connector.topic

Yes

Kafka topic name

connector.properties.bootstrap.servers

Yes

Kafka broker addresses. Use commas (,) to separated them.

connector.sink-partitioner

No

Partitioner type. The value can be fixed, round-robin, or custom.

connector.sink-partitioner-class

No

Custom partitioner. This parameter is mandatory when sink-partitioner is custom, for example, org.mycompany.MyPartitioner.

connector.sink.ignore-retraction

No

Whether to ignore the retraction message. The default value is false, indicating that the retraction message is written to Kafka as null.

update-mode

No

Data update mode. Three write modes are supported: append, retract, and upsert.

connector.properties.*

No

Native properties of Kafka

Example

create table upsertKafkaSink(
  car_id STRING,
  car_owner STRING,
  car_brand STRING,
  car_speed INT,
  primary key (car_id) not enforced
)
with (
  'connector.type' = 'upsert-kafka',
  'connector.version' = '0.11',
  'connector.topic' = 'test-topic',
  'connector.properties.bootstrap.servers' = 'xx.xx.xx.xx:9092',
  'format.type' = 'csv'
);
Parent topic: Creating a Result Table