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目錄

??????案例一

需求

代碼實現

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案例一

需求

將DataStream注冊為Table和View并進行SQL統計

代碼實現

package cn.it.sql;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.table.api.Table;
import org.apache.flink.table.api.bridge.java.StreamTableEnvironment;import java.util.Arrays;import static org.apache.flink.table.api.Expressions.$;/*** Author lanson* Desc*/
public class FlinkSQL_Table_Demo01 {public static void main(String[] args) throws Exception {//1.準備環境StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();//EnvironmentSettings settings = EnvironmentSettings.newInstance().useBlinkPlanner().inStreamingMode().build();//StreamTableEnvironment tEnv = StreamTableEnvironment.create(env, settings);StreamTableEnvironment tEnv = StreamTableEnvironment.create(env);//2.SourceDataStream<Order> orderA = env.fromCollection(Arrays.asList(new Order(1L, "beer", 3),new Order(1L, "diaper", 4),new Order(3L, "rubber", 2)));DataStream<Order> orderB = env.fromCollection(Arrays.asList(new Order(2L, "pen", 3),new Order(2L, "rubber", 3),new Order(4L, "beer", 1)));//3.注冊表// convert DataStream to TableTable tableA = tEnv.fromDataStream(orderA, $("user"), $("product"), $("amount"));// register DataStream as TabletEnv.createTemporaryView("OrderB", orderB, $("user"), $("product"), $("amount"));//4.執行查詢System.out.println(tableA);// union the two tablesTable resultTable = tEnv.sqlQuery("SELECT * FROM " + tableA + " WHERE amount > 2 " +"UNION ALL " +"SELECT * FROM OrderB WHERE amount < 2");//5.輸出結果DataStream<Order> resultDS = tEnv.toAppendStream(resultTable, Order.class);resultDS.print();env.execute();}@Data@NoArgsConstructor@AllArgsConstructorpublic static class Order {public Long user;public String product;public int amount;}
}

總結

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