FlinkSQL学习笔记(三)常用连接器举例,2024年最新大数据开发技术篇

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//1,zs,18 DataStreamSource s1 = env.socketTextStream("123.56.100.37", 9999); SingleOutputStreamOperator bean1 = s1.map(s -> { String[] arr = s.split(","); return new Bean1(Integer.parseInt(arr[0]),arr[1],Integer.parseInt(arr[2])); });

//1,beijing,1388888 DataStreamSource s2 = env.socketTextStream("123.56.100.37", 9998); SingleOutputStreamOperator bean2 = s2.map(s -> { String[] arr = s.split(","); return new Bean2(Integer.parseInt(arr[0]),arr[1],Integer.parseInt(arr[2])); });


2. socket流转表



tenv.createTemporaryView("bean1",bean1); tenv.createTemporaryView("bean2",bean2);


3. 执行建表语句



CREATE TABLE t_upsert_kafka_join3 ( id INT PRIMARY KEY NOT ENFORCED,
name STRING,
age INT,
addr STRING,
phone BIGINT
) WITH (
'connector' = 'upsert-kafka',
'topic' = 'upsert_kafka2_join',
'properties.bootstrap.servers' = '123.56.100.37:9092', 'key.format' = 'csv',
'value.format' = 'json'
)


4. 执行join语句插入



INSERT INTO t_upsert_kafka_join3 SELECT A1.id,A1.name,A1.age,A2.addr,A2.phone FROM bean1 AS A1
LEFT JOIN bean2 AS A2
ON A1.id = A2.id


5. 查看结果



tenv.executeSql("SELECT * FROM t_upsert_kafka_join3").print();


![在这里插入图片描述](https://p6-xtjj-sign.byteimg.com/tos-cn-i-73owjymdk6/ac7e59497d42474282edf6fa102f28e5~tplv-73owjymdk6-jj-mark-v1:0:0:0:0:5o6Y6YeR5oqA5pyv56S-5Yy6IEAg55So5oi3MzM5MTQ5MjgwNjA=:q75.awebp?rk3s=f64ab15b&x-expires=1772529575&x-signature=bR5eolGoTPH8fF%2BYtlURLyMQzgk%3D)


## 2、Jdbc连接器


JDBC 连接器允许使用 JDBC 驱动向任意类型的关系型数据库读取或者写入数据。如果在 DDL 中定义了`主键`,JDBC sink 将以 upsert 模式与外部系统交换 UPDATE/DELETE 消息;否则,它将以 append 模式与外部系统交换消息且不支持消费 UPDATE/DELETE 消息。Jdbc作为source的时候,支持scan模式和lookup模式,`look模式的意思参考lookup join`。  
 ![在这里插入图片描述](https://p6-xtjj-sign.byteimg.com/tos-cn-i-73owjymdk6/86ef623d652e45e09e606f25967b7ae5~tplv-73owjymdk6-jj-mark-v1:0:0:0:0:5o6Y6YeR5oqA5pyv56S-5Yy6IEAg55So5oi3MzM5MTQ5MjgwNjA=:q75.awebp?rk3s=f64ab15b&x-expires=1772529575&x-signature=mOSO8y8d%2FBOrPBO%2FNyGU3dYRRo8%3D)


### 2.1、Scan Source



CREATE TABLE flink_users ( id int primary key,
name string,
age int,
gender string
) WITH (
'connector' = 'jdbc',
'url' = 'jdbc:mysql://123.56.100.37:3306/flinktest?useSSL=false', 'table-name' = 'users',
'username' = 'root',
'password' = '123456'
)


相当于有界流,只scan一次  
 ![在这里插入图片描述](https://p6-xtjj-sign.byteimg.com/tos-cn-i-73owjymdk6/ec9701603a2c48bfb7d442c7780d1893~tplv-73owjymdk6-jj-mark-v1:0:0:0:0:5o6Y6YeR5oqA5pyv56S-5Yy6IEAg55So5oi3MzM5MTQ5MjgwNjA=:q75.awebp?rk3s=f64ab15b&x-expires=1772529575&x-signature=Om0kQ6v01kqWRsR0I4wg4e%2B2lRs%3D)


### 2.2、Sink: Streaming Append & Upsert Mode



INSERT INTO flink_users SELECT A1.id,A1.name,A1.age,A2.gender FROM bean1 AS A1
LEFT JOIN bean2 AS A2
ON A1.id = A2.id


查询结果,select的之后只scan一次  
 ![在这里插入图片描述](https://p6-xtjj-sign.byteimg.com/tos-cn-i-73owjymdk6/7f55a1d5e7ea413bbd484b37095f61eb~tplv-73owjymdk6-jj-mark-v1:0:0:0:0:5o6Y6YeR5oqA5pyv56S-5Yy6IEAg55So5oi3MzM5MTQ5MjgwNjA=:q75.awebp?rk3s=f64ab15b&x-expires=1772529575&x-signature=vkQpUxkp1HowELYN0rlkQI3at8k%3D)


## 3、CDC连接器


适用于 Apache FlinkCDC 连接器是一组适用于 Apache Flink 的源连接器,使用`更改数据捕获 (CDC) 从不同的数据库引入更改`。 适用于 `Apache Flink 的 CDC 连接器集成了 Debezium` 作为捕获数据更改的引擎。所以它可以充分利用Debezium的能力。


github地址:<https://github.com/ververica/flink-cdc-connectors?tab=readme-ov-file>


### 3.1、Flink-CDC源码编译


1. 下载源码  
 <https://github.com/apache/flink-cdc/blob/release-2.0/pom.xml>  
 选择合适的版本、文章中用的事1.14.4,这里选择1.13.1版本  
 ![在这里插入图片描述](https://p6-xtjj-sign.byteimg.com/tos-cn-i-73owjymdk6/6c7c377ce702486098621e3a16ae4a3c~tplv-73owjymdk6-jj-mark-v1:0:0:0:0:5o6Y6YeR5oqA5pyv56S-5Yy6IEAg55So5oi3MzM5MTQ5MjgwNjA=:q75.awebp?rk3s=f64ab15b&x-expires=1772529575&x-signature=DwCVJidP4I%2B%2FS%2Fb0lw0Fk%2FgP67w%3D)
2. 在idea中,通过project from version control导入maven项目,源码修改如下:  
 ①:删除包括测试等不用的项目,避免编译多余的项目  
 ②:修改flink版本和Scala版本,为了匹配我们现在使用的flink版本  
 ③:修改项目的groupId和version,定义新的flink版本  
 `这一步其实就是相当于修改源码,实际编程过程中,遇到很多细节性的错误,这里不做列举`  
 ![在这里插入图片描述](https://p6-xtjj-sign.byteimg.com/tos-cn-i-73owjymdk6/f46b6fc4c0e147cebecbf45fcf50dbf9~tplv-73owjymdk6-jj-mark-v1:0:0:0:0:5o6Y6YeR5oqA5pyv56S-5Yy6IEAg55So5oi3MzM5MTQ5MjgwNjA=:q75.awebp?rk3s=f64ab15b&x-expires=1772529575&x-signature=K3RLCmJZZGLwGxi7T%2B1mDcquwKQ%3D)
3. 编译源码,打包  
 这里直接在idea中选择install,从而可以成功的安装到本地  
 ![在这里插入图片描述](https://p6-xtjj-sign.byteimg.com/tos-cn-i-73owjymdk6/39b04a662a5e4cfbb9cd8b8604f49a24~tplv-73owjymdk6-jj-mark-v1:0:0:0:0:5o6Y6YeR5oqA5pyv56S-5Yy6IEAg55So5oi3MzM5MTQ5MjgwNjA=:q75.awebp?rk3s=f64ab15b&x-expires=1772529575&x-signature=azAXCgUi3OPyxVOcbIevxkkCAzM%3D)


### 3.2 、mysql开启binlog


1. 修改配置文件/etc/mysql/my.cnf  
 github参考连接:<https://github.com/apache/flink-cdc/blob/master/docs/content/docs/connectors/cdc-connectors/mysql-cdc.md>  
 ![在这里插入图片描述](https://p6-xtjj-sign.byteimg.com/tos-cn-i-73owjymdk6/8ecb6f38540e426da7a42e921622ea91~tplv-73owjymdk6-jj-mark-v1:0:0:0:0:5o6Y6YeR5oqA5pyv56S-5Yy6IEAg55So5oi3MzM5MTQ5MjgwNjA=:q75.awebp?rk3s=f64ab15b&x-expires=1772529575&x-signature=3lB2cBjKpDXxlInb3h1XgDBOebE%3D)  
 [mysqld]:<https://stackoverflow.com/questions/44298071/how-to-fix-mysql-error-found-option-without-preceding-group-in-config-file>
2. 查看binlog是否开启



show variables like 'log_%';


![在这里插入图片描述](https://p6-xtjj-sign.byteimg.com/tos-cn-i-73owjymdk6/cc46093c7a6848a892f6558b1f5d3510~tplv-73owjymdk6-jj-mark-v1:0:0:0:0:5o6Y6YeR5oqA5pyv56S-5Yy6IEAg55So5oi3MzM5MTQ5MjgwNjA=:q75.awebp?rk3s=f64ab15b&x-expires=1772529575&x-signature=m0JSxrFBFdExEsoKVgZEg68XbuM%3D)


3. 查看master状态,即binlog的状态



show master status;


![在这里插入图片描述](https://p6-xtjj-sign.byteimg.com/tos-cn-i-73owjymdk6/490343330f654600bd60c8aef2954ae6~tplv-73owjymdk6-jj-mark-v1:0:0:0:0:5o6Y6YeR5oqA5pyv56S-5Yy6IEAg55So5oi3MzM5MTQ5MjgwNjA=:q75.awebp?rk3s=f64ab15b&x-expires=1772529575&x-signature=cKm0wQRFJGDKfhZgzJ17yDzJLXg%3D)


4. 建表后查看binlog信息



show binlog events in 'mysql-bin.000001';


![在这里插入图片描述](https://p6-xtjj-sign.byteimg.com/tos-cn-i-73owjymdk6/175009da229a4967a03c8faa99d19383~tplv-73owjymdk6-jj-mark-v1:0:0:0:0:5o6Y6YeR5oqA5pyv56S-5Yy6IEAg55So5oi3MzM5MTQ5MjgwNjA=:q75.awebp?rk3s=f64ab15b&x-expires=1772529575&x-signature=5aUpCfmZVJnwW6foDQqsoeb9hW8%3D)


### 3.3、mysql cdc连接器测试


使用方式参考连接:<https://github.com/apache/flink-cdc/blob/master/docs/content/docs/connectors/cdc-connectors/mysql-cdc.md>


1. 开启Checkpoint



env.enableCheckpointing(1000, CheckpointingMode.EXACTLY_ONCE); env.getCheckpointConfig().setCheckpointStorage("file:///c:/checkpoint");


2. 创建SQL表



CREATE TABLE flink_score ( id INT, name STRING, gender STRING, score DOUBLE, PRIMARY KEY(id) NOT ENFORCED ) WITH ( 'connector' = 'mysql-cdc', 'hostname' = '123.56.100.37', 'port' = '3306', 'username' = 'root', 'password' = '123456', 'database-name' = 'flinktest', 'table-name' = 'score' )


3. 测试是否可以查询到MySQL更新得到的数据  
 ![在这里插入图片描述](https://p6-xtjj-sign.byteimg.com/tos-cn-i-73owjymdk6/5926d94647aa4c9bbff77998c97ccd9a~tplv-73owjymdk6-jj-mark-v1:0:0:0:0:5o6Y6YeR5oqA5pyv56S-5Yy6IEAg55So5oi3MzM5MTQ5MjgwNjA=:q75.awebp?rk3s=f64ab15b&x-expires=1772529575&x-signature=R216vfZZxR7z9rtVyHxPuR%2BDjFQ%3D)
4. 测试复杂的SQL逻辑—`分组topN`



SELECT gender , name , score_amt , rn FROM ( SELECT gender , name , score_amt , row_number() over(partition by gender order by score_amt) as rn FROM ( SELECT gender , name , sum(score) as score_amt FROM flink_score GROUP BY gender,name )O1

)O2

WHERE rn<=2


![在这里插入图片描述](https://p6-xtjj-sign.byteimg.com/tos-cn-i-73owjymdk6/febca1c9dadb4a45a3d8162c432dc70e~tplv-73owjymdk6-jj-mark-v1:0:0:0:0:5o6Y6YeR5oqA5pyv56S-5Yy6IEAg55So5oi3MzM5MTQ5MjgwNjA=:q75.awebp?rk3s=f64ab15b&x-expires=1772529575&x-signature=t6hZOEfkVhQ3fIL%2FdbL3my7vHaU%3D)


![img](https://p6-xtjj-sign.byteimg.com/tos-cn-i-73owjymdk6/98d0c89b60cd4a9d9c5a505129a40e08~tplv-73owjymdk6-jj-mark-v1:0:0:0:0:5o6Y6YeR5oqA5pyv56S-5Yy6IEAg55So5oi3MzM5MTQ5MjgwNjA=:q75.awebp?rk3s=f64ab15b&x-expires=1772529575&x-signature=pe%2FNcCLtVBd%2FY6bwSFiBnXpDoSw%3D)
![img](https://p6-xtjj-sign.byteimg.com/tos-cn-i-73owjymdk6/f5848624fb66415daaec9e0dc678afa0~tplv-73owjymdk6-jj-mark-v1:0:0:0:0:5o6Y6YeR5oqA5pyv56S-5Yy6IEAg55So5oi3MzM5MTQ5MjgwNjA=:q75.awebp?rk3s=f64ab15b&x-expires=1772529575&x-signature=zqsPoUonccrbtn65pHdWgF8YI%2Bo%3D)

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