Pig-無法轉儲數據

我有兩個數據集的一個電影和其它的評級Pig-無法轉儲數據

電影數據看起來像

MovieID#Title#Genre 
1#Toy Story (1995)#Animation|Children's|Comedy 
2#Jumanji (1995)#Adventure|Children's|Fantasy 
3#Grumpier Old Men (1995)#Comedy|Romance

收視數據看起來像

UserID#MovieID#Ratings#RatingsTimestamp 
1#1193#5#978300760 
1#661#3#978302109 
1#914#3#978301968

我的劇本是爲如下

1) movies_data = LOAD '/user/admin/MoviesDataset/movies_new.dat' USING PigStorage('#') AS (movieid:int, 
    moviename:chararray,moviegenere:chararray); 

    2) ratings_data = LOAD '/user/admin/RatingsDataset/ratings_new.dat' USING PigStorage('#') AS (Userid:int, 
    movieid:int,ratings:int,timestamp:long); 

    3) moviedata_ratingsdata_join = JOIN movies_data BY movieid, ratings_data BY movieid; 

    4) moviedata_ratingsdata_join_group = GROUP moviedata_ratingsdata_join BY movies_data.movieid; 

    5) moviedata_ratingsdata_averagerating = FOREACH moviedata_ratingsdata_join_group GENERATE group, 
    AVG(moviedata_ratingsdata_join.ratings) AS Averageratings, (moviedata_ratingsdata_join.Userid) AS userid; 

    6) DUMP moviedata_ratingsdata_averagerating;

如果刪除第6行，腳本成功執行

爲什麼我不能DUMP關係產生第5行中我得到這個錯誤

2017-03-25 06:46:50,332 [main] ERROR org.apache.pig.tools.pigstats.PigStats - ERROR 0: org.apache.pig.backend.executionengine.ExecException: ERROR 0: Exception while executing (Name: moviedata_ratingsdata_join_group: Local Rearrange[tuple]{int}(false) - scope-95 Operator Key: scope-95): org.apache.pig.backend.executionengine.ExecException: ERROR 0: Exception while executing (Name: moviedata_ratingsdata_averagerating: New For Each(false,false)[bag] - scope-83 Operator Key: scope-83): org.apache.pig.backend.executionengine.ExecException: ERROR 0: Scalar has more than one row in the output. 1st : (1,Toy Story (1995),Animation|Children's|Comedy), 2nd :(2,Jumanji (1995),Adventure|Children's|Fantasy) (common cause: "JOIN" then "FOREACH ... GENERATE foo.bar" should be "foo::bar")

？

來源

2017-03-25 Nishant123

使用disambiguate operator（::）後JOIN，COGROUP，CROSS，或FLATTEN運營商識別字段名。

關係movies_data和ratings_data都有一列movieid。在形成關係moviedata_ratingsdata_join_group時，請使用::運營商來確定要使用哪個列movieid。

所以你4)會是什麼樣子，

4) moviedata_ratingsdata_join_group = GROUP moviedata_ratingsdata_join BY movies_data::movieid;

來源

2017-03-25 14:30:08 franklinsijo

Pig-無法轉儲數據

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