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一. 背景

FLINK 任务从一个数据源读取数据, 写入多个sink端.

二. 官方实例

写入多个Sink语句时，需要以BEGIN STATEMENT SET;开头，以END;结尾。

--源表
CREATE TEMPORARY TABLE datagen_source (name VARCHAR,score BIGINT
) WITH ('connector' = 'datagen'
);--结果表A
CREATE TEMPORARY TABLE blackhole_sinkA(name VARCHAR,score BIGINT
) WITH ('connector' = 'blackhole' 
);--结果表B
CREATE TEMPORARY TABLE blackhole_sinkB(name VARCHAR,score BIGINT
) WITH ('connector' = 'blackhole' 
);--DML
BEGIN STATEMENT SET;      --写入多个Sink时，必填。
INSERT INTO blackhole_sinkA SELECT UPPER(name), sum(score) FROM datagen_source GROUP BY UPPER(name);
INSERT INTO blackhole_sinkB SELECT LOWER(name), max(score) FROM datagen_source GROUP BY LOWER(name);
END;      --写入多个Sink时，必填。

三. 实操

3.1. 启动Standlone集群

进入到flink引擎包目录, 启动Standlone模式.

./bin/start-cluster.sh

3.2. 启动flink sql-client.

./bin/sql-client.sh embedded

3.3. 执行sql

Flink SQL> CREATE TEMPORARY TABLE datagen_source (
>   name VARCHAR,
>   score BIGINT
> ) WITH (
>   'connector' = 'datagen'
> );
[INFO] Execute statement succeed.Flink SQL> CREATE TEMPORARY TABLE blackhole_sinkA(
>   name VARCHAR,
>   score BIGINT
> ) WITH (
>   'connector' = 'blackhole'
> );
>
[INFO] Execute statement succeed.Flink SQL> CREATE TEMPORARY TABLE blackhole_sinkB(
>   name VARCHAR,
>   score BIGINT
> ) WITH (
>   'connector' = 'blackhole'
> );
>
[INFO] Execute statement succeed.Flink SQL> BEGIN STATEMENT SET;
[INFO] Begin a statement set.Flink SQL> INSERT INTO blackhole_sinkA
>   SELECT UPPER(name), sum(score)
>   FROM datagen_source
>   GROUP BY UPPER(name);
[INFO] Add SQL update statement to the statement set.Flink SQL> INSERT INTO blackhole_sinkB
>   SELECT LOWER(name), max(score)
>   FROM datagen_source
>   GROUP BY LOWER(name);
[INFO] Add SQL update statement to the statement set.Flink SQL> END;
[INFO] Submitting SQL update statement to the cluster...
[INFO] SQL update statement has been successfully submitted to the cluster:
Job ID: 37a1390129c356374601a267cb8080b6

3.4. 查看flink ui

查看flink ui页面,验证结论.

http://master01:8081/#/job/37a1390129c356374601a267cb8080b6/overview