Tableapi & SQL and MySQL data query of Flink

Use Tbale&SQL And Flink JDBC Connector from MYSQL Database table SELECT Select data .

Sample environment

java.version: 1.8.x
flink.version: 1.11.1
kafka：2.11

Sample data source  （ Project code cloud download ）

Flink System examples And Build development environment and data

Sample module  （pom.xml）

Flink System examples And TableAPI & SQL And Sample module

SelectToMysql.java

package com.flink.examples.mysql;

import org.apache.flink.api.common.functions.FlatMapFunction;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.table.api.EnvironmentSettings;
import org.apache.flink.table.api.Table;
import org.apache.flink.table.api.bridge.java.StreamTableEnvironment;
import org.apache.flink.types.Row;
import org.apache.flink.util.Collector;

import static org.apache.flink.table.api.Expressions.$;

/**
 * @Description  Use Tbale&SQL And Flink JDBC Connector from MYSQL Database table SELECT Select data .
 */
public class SelectToMysql {
    /**
      Official reference ：https://ci.apache.org/projects/flink/flink-docs-release-1.11/dev/table/connectors/jdbc.html

      Partition scan 
      To speed up parallelism Source Data reading in task instance ,Flink by JDBC Table provides partition scanning function .
         scan.partition.column： The column name used to partition the input .
         scan.partition.num： Partition number .
         scan.partition.lower-bound： The minimum value of the first partition .
         scan.partition.upper-bound： The maximum value of the last partition .
     */

    //flink-jdbc-1.11.1 How to write it , All attribute names are in JdbcTableSourceSinkFactory The factory class defines 
    static String table_sql =
            "CREATE TABLE my_users (\n" +
            "  id BIGINT,\n" +
            "  name STRING,\n" +
            "  age INT,\n" +
            "  status INT,\n" +
            "  PRIMARY KEY (id) NOT ENFORCED\n" +
            ") WITH (\n" +
            "  'connector.type' = 'jdbc',\n" +
            "  'connector.url' = 'jdbc:mysql://192.168.110.35:3306/flink?useUnicode=true&characterEncoding=utf-8', \n" +
            "  'connector.driver' = 'com.mysql.jdbc.Driver', \n" +
            "  'connector.table' = 'users', \n" +
            "  'connector.username' = 'root',\n" +
            "  'connector.password' = 'password', \n" +
            "  'connector.read.fetch-size' = '3' \n" +
            ")";
    public static void main(String[] args) throws Exception {
        // structure StreamExecutionEnvironment
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        // structure EnvironmentSettings  And designate Blink Planner
        EnvironmentSettings bsSettings = EnvironmentSettings.newInstance().useBlinkPlanner().inStreamingMode().build();
        // structure StreamTableEnvironment
        StreamTableEnvironment tEnv = StreamTableEnvironment.create(env, bsSettings);
        // register mysql Data dimension table 
        tEnv.executeSql(table_sql);

        String sql = "select id,name,age,status from my_users";
        // The first one is ： perform SQL
        //Table table = tEnv.sqlQuery(sql);

        // The second kind ： Execution statements are assembled through methods 
        Table table = tEnv.from("my_users").select($("id"), $("name"), $("age"), $("status")).where($("status").isEqual(0));

        // Print the field structure 
        table.printSchema();

        //table  Turn into  dataStream  flow 
        DataStream<Row> behaviorStream = tEnv.toAppendStream(table, Row.class);
        behaviorStream.flatMap(new FlatMapFunction<Row, Object>() {
            @Override
            public void flatMap(Row value, Collector<Object> out) throws Exception {
                System.out.println(value.toString());
                Thread.sleep(1 * 1000);
            }
        }).print();
        env.execute();
    }
}

  Print the results

root
 |-- id: BIGINT NOT NULL
 |-- name: STRING
 |-- age: INT
 |-- status: INT

1,nike,16,0
2,nike,18,0