flink sql 读取kafka 多个表 demo 1.17.0

好的，以下是一个 Flink SQL 读取 Kafka 多个表的示例代码，使用的是 Flink 1.17.0 版本：

import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.table.api.bridge.java.StreamTableEnvironment;

public class KafkaMultipleTablesDemo {
    public static void main(String[] args) throws Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        StreamTableEnvironment tableEnv = StreamTableEnvironment.create(env);

        // 定义 Kafka 连接相关的配置
        String kafkaBootstrapServers = "localhost:9092";
        String kafkaGroupID = "flink-table-group";
        String kafkaTopicA = "topic_a";
        String kafkaTopicB = "topic_b";

        // 注册 Kafka 主题 A 为表 a
        tableEnv.executeSql("CREATE TABLE a (\n" +
                "  id BIGINT,\n" +
                "  name STRING,\n" +
                "  PRIMARY KEY (id) NOT ENFORCED\n" +
                ") WITH (\n" +
                "  'connector' = 'kafka',\n" +
                "  'topic' = '" + kafkaTopicA + "',\n" +
                "  'properties.bootstrap.servers' = '" + kafkaBootstrapServers + "',\n" +
                "  'properties.group.id' = '" + kafkaGroupID + "',\n" +
                "  'format' = 'json',\n" +
                "  'scan.startup.mode' = 'earliest-offset'\n" +
                ")");

        // 注册 Kafka 主题 B 为表 b
        tableEnv.executeSql("CREATE TABLE b (\n" +
                "  id BIGINT,\n" +
                "  age INT,\n" +
                "  PRIMARY KEY (id) NOT ENFORCED\n" +
                ") WITH (\n" +
                "  'connector' = 'kafka',\n" +
                "  'topic' = '" + kafkaTopicB + "',\n" +
                "  'properties.bootstrap.servers' = '" + kafkaBootstrapServers + "',\n" +
                "  'properties.group.id' = '" + kafkaGroupID + "',\n" +
                "  'format' = 'json',\n" +
                "  'scan.startup.mode' = 'earliest-offset'\n" +
                ")");

        // 执行 SQL 查询
        tableEnv.executeSql("SELECT a.name, b.age\n" +
                "FROM a JOIN b ON a.id = b.id").print();

        env.execute("Kafka Multiple Tables Demo");
    }
}

这个示例代码中，我们使用 `StreamTableEnvironment` 来注册 Kafka 主题 A 和 B 为表 a 和 b，然后在 SQL 查询中将它们连接起来。注意，这里的 Kafka 连接相关的配置需要根据你的实际情况进行修改。最后，我们使用 `env.execute()` 来执行 Flink 作业。