【云星数据---Apache Flink实战系列(精品版)】：Apache Flink批处理API详解与编程实战010--DateSet实用API详解010

DateSet的API详解十

leftOuterJoin

def leftOuterJoin[O](other: DataSet[O], strategy: JoinHint): UnfinishedOuterJoinOperation[T, O]def leftOuterJoin[O](other: DataSet[O]): UnfinishedOuterJoinOperation[T, O]An outer join on the left side.左外连接。

leftOuterJoin示例一

执行程序：

//1.定义case classcase class Rating(name: String, category: String, points: Int)//2.定义 DataSet[Rating]val ratings: DataSet[Rating] = benv.fromElements(Rating("moon","youny1",3),Rating("sun","youny2",4),Rating("cat","youny3",1),Rating("dog","youny4",5),Rating("tiger","youny4",5))//3.定义DataSet[(String, String)] val movies: DataSet[(String, String)]  = benv.fromElements(("moon","ok"),("dog","good"),("cat","notbad"),("sun","nice"),("water","nice"))//4.两个dataset进行左外连接，指定方法val result1 = movies.leftOuterJoin(ratings).where(0).equalTo("name"){    (m, r) => (m._1, if (r == null) -1 else r.points)}//5.显示结果result1.collect

执行结果：

res26: Seq[(String, Int)] = Buffer((moon,3), (dog,5), (cat,1), (sun,4), (water,-1))

web ui中的执行效果：

leftOuterJoin示例二

执行程序：

//1.定义case classcase class Rating(name: String, category: String, points: Int)//2.定义 DataSet[Rating]val ratings: DataSet[Rating] = benv.fromElements(Rating("moon","youny1",3),Rating("sun","youny2",4),Rating("cat","youny3",1),Rating("dog","youny4",5),Rating("tiger","youny4",5))//3.定义DataSet[(String, String)] val movies: DataSet[(String, String)]  = benv.fromElements(("moon","ok"),("dog","good"),("cat","notbad"),("sun","nice"),("water","nice"))//4.两个dataset进行左外连接，指定连接暗示，并指定连接方法val result1 = movies.leftOuterJoin(ratings, JoinHint.REPARTITION_SORT_MERGE).where(0).equalTo("name"){    (m, r) => (m._1, if (r == null) -1 else r.points)}//5.显示结果result1 .collect

执行结果：

res26: Seq[(String, Int)] = Buffer((cat,1), (dog,5), (moon,3), (sun,4), (water,-1))

暗示项目说明：

左外连接支持以下项目：    JoinHint.OPTIMIZER_CHOOSES    JoinHint.BROADCAST_HASH_SECOND    JoinHint.REPARTITION_HASH_SECOND    JoinHint.REPARTITION_SORT_MERGE

rightOuterJoin

def rightOuterJoin[O](other: DataSet[O], strategy: JoinHint): UnfinishedOuterJoinOperation[T, O]def rightOuterJoin[O](other: DataSet[O]): UnfinishedOuterJoinOperation[T, O]An outer join on the right side.右外连接

rightOuterJoin示例一

执行程序：

//1.定义DataSet[(String, String)] val movies: DataSet[(String, String)]  = benv.fromElements(("moon","ok"),("dog","good"),("cat","notbad"),("sun","nice"))//2.定义 DataSet[Rating]case class Rating(name: String, category: String, points: Int)val ratings: DataSet[Rating] = benv.fromElements(Rating("moon","youny1",3),Rating("sun","youny2",4),Rating("cat","youny3",1),Rating("dog","youny4",5))//3.两个dataset进行左外连接，指定连接方法val result1 = movies.rightOuterJoin(ratings).where(0).equalTo("name"){    (m, r) => (m._1, if (r == null) -1 else r.points)}//5.显示结果result1.collect

执行结果：

res33: Seq[(String, Int)] = Buffer((moon,3), (sun,4), (cat,1), (dog,5))

web ui中的执行效果：

rightOuterJoin示例二

执行程序：

//1.定义DataSet[(String, String)] val movies: DataSet[(String, String)]  = benv.fromElements(("moon","ok"),("dog","good"),("cat","notbad"),("sun","nice"))//2.定义 DataSet[Rating]case class Rating(name: String, category: String, points: Int)val ratings: DataSet[Rating] = benv.fromElements(Rating("moon","youny1",3),Rating("sun","youny2",4),Rating("cat","youny3",1),Rating("dog","youny4",5))//3.两个dataset进行左外连接，暗示连接方式，指定连接方法val result1 = movies.rightOuterJoin(ratings,JoinHint.BROADCAST_HASH_FIRST).where(0).equalTo("name"){    (m, r) => (m._1, if (r == null) -1 else r.points)}//5.显示结果result1.collect

执行结果：

res34: Seq[(String, Int)] = Buffer((moon,3), (sun,4), (cat,1), (dog,5))

暗示项目说明：

左外连接支持以下项目：    JoinHint.OPTIMIZER_CHOOSES    JoinHint.BROADCAST_HASH_FIRST    JoinHint.REPARTITION_HASH_FIRST    JoinHint.REPARTITION_SORT_MERGE