1.数据
订单表,分别是店铺id、用户id和支付金额
"店铺id,用户id,支付金额",
"shop-1,user-1,1",
"shop-1,user-2,1",
"shop-1,user-2,1",
"shop-1,user-3,1",
"shop-1,user-3,1",
"shop-1,user-1,1",
"shop-1,user-2,1",
"shop-1,user-4,1",
"shop-2,user-4,1",
"shop-2,user-4,1",
"shop-2,user-2,1"
2.可运行案例
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
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 org.apache.flink.types.Row;
public class Test03 {
public static void main(String[] args) throws Exception {
// 1. 创建流式执行环境
StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
// 2.创建表执行环境
StreamTableEnvironment tableEnv = StreamTableEnvironment.create(env);
// 3.读取数据源
SingleOutputStreamOperator jsonStream = env
.fromElements("shop-1,user-1,1",
"shop-1,user-2,1",
"shop-1,user-2,1",
"shop-1,user-3,1",
"shop-1,user-3,1",
"shop-1,user-1,1",
"shop-1,user-2,1",
"shop-1,user-4,1",
"shop-2,user-4,1",
"shop-2,user-4,1",
"shop-2,user-2,1"
);
// 4.流转换为表
Table table = tableEnv.fromDataStream(jsonStream);
// 5. 把注册为一个临时视图
tableEnv.createTemporaryView("tableTmp", table);
// 6.求每个商店的用户数
Table table1 = tableEnv.sqlQuery("select shop_id,sum(num) as num,sum(gmv) as gmv from (select shop_id,user_id, 1 as num,sum(gmv) as gmv from (select SPLIT_INDEX(f0,',',0) as shop_id,SPLIT_INDEX(f0,',',1) as user_id,cast(SPLIT_INDEX(f0,',',2) as bigint) as gmv from tableTmp) t1 group by shop_id,user_id) t2 group by shop_id");
// 7.打印
tableEnv.toRetractStream(table1, Row.class).print(">>>>>>");
// 8.执行
env.execute("test");
}
}
sql:
select
shop_id,
sum(num) as num,
sum(gmv) as gmv
from
(
select
shop_id,
user_id,
1 as num,
sum(gmv) as gmv
from
(
select
SPLIT_INDEX(f0, ',', 0) as shop_id,
SPLIT_INDEX(f0, ',', 1) as user_id,
cast(SPLIT_INDEX(f0, ',', 2) as bigint) as gmv
from
tableTmp
) t1
group by
shop_id,
user_id
) t2
group by
shop_id
3.运行结果
>>>>>>:7> (true,+U[shop-2, 2, 3])
>>>>>>:1> (true,+U[shop-1, 4, 8])
>>>>>>:7> (true,+I[shop-2, 1, 1])
>>>>>>:1> (true,+I[shop-1, 1, 1])
>>>>>>:1> (false,-U[shop-1, 1, 1])
>>>>>>:7> (false,-U[shop-2, 1, 1])
>>>>>>:1> (true,+U[shop-1, 2, 2])
>>>>>>:7> (true,+U[shop-2, 2, 2])
>>>>>>:1> (false,-U[shop-1, 2, 2])
>>>>>>:7> (false,-U[shop-2, 2, 2])
>>>>>>:1> (true,+U[shop-1, 1, 1])
>>>>>>:7> (true,+U[shop-2, 1, 1])
>>>>>>:1> (false,-U[shop-1, 1, 1])
>>>>>>:7> (false,-U[shop-2, 1, 1])
>>>>>>:7> (true,+U[shop-2, 2, 3])
>>>>>>:1> (true,+U[shop-1, 2, 3])
>>>>>>:1> (false,-U[shop-1, 2, 3])
>>>>>>:1> (true,+U[shop-1, 3, 4])
>>>>>>:1> (false,-U[shop-1, 3, 4])
>>>>>>:1> (true,+U[shop-1, 2, 3])
>>>>>>:1> (false,-U[shop-1, 2, 3])
>>>>>>:1> (true,+U[shop-1, 3, 5])
>>>>>>:1> (false,-U[shop-1, 3, 5])
>>>>>>:1> (true,+U[shop-1, 2, 3])
>>>>>>:1> (false,-U[shop-1, 2, 3])
>>>>>>:1> (true,+U[shop-1, 3, 6])
>>>>>>:1> (false,-U[shop-1, 3, 6])
>>>>>>:1> (true,+U[shop-1, 4, 7])
>>>>>>:1> (false,-U[shop-1, 4, 7])
>>>>>>:1> (true,+U[shop-1, 3, 6])
>>>>>>:1> (false,-U[shop-1, 3, 6])
>>>>>>:1> (true,+U[shop-1, 4, 8])
4.原理
Flink回撤流原理