【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011--DateSet实用API详解011

DateSet的API详解十一

fullOuterJoin

def fullOuterJoin[O](other: DataSet[O], strategy: JoinHint): UnfinishedOuterJoinOperation[T, O]deffullOuterJoin[O](other: DataSet[O]): UnfinishedOuterJoinOperation[T, O]Special fullOuterJoin operation for explicitly telling the system what join strategy to use.全外连接

fullOuterJoin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进行全外连接，指定连接方法val result1 = movies.fullOuterJoin(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进行全外连接，指定连接方法val result1 = movies.fullOuterJoin(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：

res41: Seq[(String, Int)] = Buffer((cat,1), (dog,5), (moon,3), (sun,4))

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