使用FlinkSQL将数据写入到ClickHouse

使用FlinkSQL将地区主题数据写入到ClickHouse

一、需求分析与思路

1. 定义Table流环境
2. 把数据源定义为动态表
3. 通过SQL查询出结果表
4. 把结果表转换为数据流
5. 把数据流写入目标数据库

如果是Flink官方支持的数据库，也可以直接把目标数据表定义为动态表，用insert into 写入。由于ClickHouse目前官方没有支持的jdbc连接器（目前支持Mysql、 PostgreSQL、Derby）。

阿里云有实现好的connector, 我们使用这个connector.参考地址: https://help.aliyun.com/document_detail/185696.html?spm=a2c4g.11186623.6.574.d9c541ea3J78mc

二、功能实现

数据来源于topic: dwm_order_wide

2.1 导入ClickHouse连接器

<dependency>
    <groupId>com.aliyungroupId>
    <artifactId>flink-connector-clickhouseartifactId>
    <version>1.11.0version>
dependency>

注意:

1. 由于该连接器目前在远程的maven仓库中找不到, 我们需要下载该连接器, 然后安装到本地仓库使用
2. 下载地址: https://clickhouse-release-open-access.oss-cn-shanghai.aliyuncs.com/doc-data/flink-connector-clickhouse-1.11.0.jar?spm=a2c4g.11186623.2.6.d9c541ea3J78mc&file=flink-connector-clickhouse-1.11.0.jar
3. 假设jar包被下载在如下目录: C:\Users\lzc\Desktop\connector
4. 安装jar到本地仓库(需要保证mvn命令已经配置到了path中):

mvn install:install-file -Dfile=C:\Users\lzc\Desktop\connector\flink-connector-clickhouse-1.11.0.jar
 -DgroupId=com.aliyun -DartifactId=flink-connector-clickhouse -Dversion=1.11.0 -Dpackaging=jar

2.2 在ClickHouse中创建表

use gmall2021;
create table province_stats_2021 (
   stt DateTime,
   edt DateTime,
   province_id  UInt64,
   province_name String,
   area_code String ,
   iso_code String,
   iso_3166_2 String , 
   order_amount Decimal64(2),
   order_count UInt64, 
   ts UInt64
)engine =ReplacingMergeTree( ts)
        partition by  toYYYYMMDD(stt)
        order by   (stt,edt,province_id );

2.3 具体实现代码

package com.gmall.realtime.app.dws;

import com.gmall.realtime.app.BaseSqlAPP;
import org.apache.flink.table.api.Table;
import org.apache.flink.table.api.bridge.java.StreamTableEnvironment;

public class DWSProvinceStateApp extends BaseSqlAPP {
    public static void main(String[] args) {
        new DWSProvinceStateApp().init(30003,2,"DWSProvinceStateApp");
    }

    @Override
    public void run(StreamTableEnvironment tenv) {

        //1.建表与source关联  t1 dwm_order_wide
       tenv.executeSql("create table order_wide(" +
                " province_id  bigint, " +
                " province_name  string, " +
                " province_area_code  string, " +
                " province_iso_code  string, " +
                " province_3166_2_code  string, " +
                " order_id  bigint, " +
                " split_total_amount  decimal(12,2), " +
                " create_time  string, " +
                " event_time  as to_timestamp(create_time), " +
                " watermark for event_time as event_time - interval '5' second " +
                ")with(" +
                " 'connector' = 'kafka'," +
                " 'properties.bootstrap.servers' = 'hadoop162:9092,hadoop163:9092,hadoop164:9092', " +
                " 'properties.group.id' = 'DWSProvinceStateApp', " +
                " 'topic' = 'dwm_order_wide', " +
                " 'scan.startup.mode' = 'latest-offset', " +
                " 'format' = 'json' " +
                ")");


      //2. 建表与sink表关联 t2
        tenv.executeSql("create table province_stats_2021(" +
                " stt string, " +
                " edt string, " +
                " province_id  bigint, " +
                " province_name  string, " +
                " area_code  string, " +
                " iso_code  string, " +
                " iso_3166_2  string, " +
                " order_amount  decimal(20,2), " +
                " order_count  bigint, " +
                " ts  bigint, " +
                " primary key(stt,edt,province_id) not enforced" +
                ")with(" +
                " 'connector' = 'clickhouse', " +
                " 'url' = 'clickhouse://hadoop162:8123', " +
                " 'database-name' = 'gmall2021', " +
                " 'table-name' = 'province_stats_2021', " +
                " 'sink.batch-size' = '100', " +
                " 'sink.flush-interval' = '1000', " +
                " 'sink.max-retries' = '3' " +
                ")");



        //3.查询t1，把结果写入到t2
        final Table table = tenv.sqlQuery("select " +
                " date_format(tumble_start(event_time,  interval '10' second),'yyyy-MM-dd HH:mm:ss'), " +
                " date_format(tumble_end(event_time,  interval '10' second),'yyyy-MM-dd HH:mm:ss'), " +
                " province_id, " +
                " province_name, " +
                " province_area_code, " +
                " province_iso_code, " +
                " province_3166_2_code, " +
                " sum(split_total_amount) order_amount, " +
                " count(distinct order_id) order_count, " +
                " unix_timestamp()*1000  ts" +
                " from  order_wide " +
                " group by " +
                " tumble(event_time, interval '10' second)," +
                " province_id, " +
                " province_name, " +
                " province_area_code, " +
                " province_iso_code, " +
                " province_3166_2_code");

        table.executeInsert("province_stats_2021");


    }
}