apache pig 中的总和：错误 1045

Question

我想用 pig

计算 2 和的除法

A = LOAD 's3://input' AS (filed1:chararray, filed2:int, field3:float, field4:float);
filtered_1 = FILTER A BY field3 >= 10;
filtered_2 = FILTER filtered_1  BY field4 >= 50;
grouped = GROUP filtered_2 BY field1;
B = FOREACH grouped GENERATE group as field1, SUM(A.field3)/SUM(A.field4) AS A_avg;

除了我在运行最后一个命令时出现此错误：

ERROR grunt.Grunt: ERROR 1045: <line 5, column 55> Could not infer the matching function for org.apache.pig.builtin.SUM as multiple or none of them fit. Please use an explicit cast.

而且我找不到原因，因为我在执行求和之前使用了 GROUP，而且我已经阅读了 SUM 文档，但我不知道与我写的有什么不同

Answer 1

grouped = GROUP filtered_2 BY field1;

grouped has no ACCESS to alias A . 

B = FOREACH grouped GENERATE group as field1, SUM(A.field3)/SUM(A.field4) AS A_avg;

"FOREACH grouped " has no access to alias A but directly to fields (field3, field4)






filtered_1 = FILTER A BY field3 >= 10;
filtered_2 = FILTER filtered_1  BY field4 >= 50;


All you are doing in this statement is an AND operation 

filtered_3 = FILTER A BY field3 >= 10 AND field4 >= 50;

Now
grouped = GROUP filtered_3 BY field1;
B = FOREACH grouped GENERATE group as field1, SUM(filtered_3.field3)/SUM(filtered_3.field4) AS A_avg;

apache pig 中的总和：错误 1045

sum in apache pig: error 1045

sum

apache-pig