＆＃34;无效的标量投影＆＃34;在JOIN之后出错，然后在Pig中进行过滤

Question

我正在使用Pig 0.12.1。在FILTER JOIN后LEFT OUTER A = LOAD '$file1' USING PigStorage('\t') AS (idA:int, manufacturer:chararray); B = LOAD '$file2' USING PigStorage('\t') AS (idB:int, price:float); C = JOIN A BY idA LEFT OUTER, B BY idB; D = FILTER C BY price > 2.0; 后，为什么会出现错误？

这是一个修改过的例子：

D

为什么我会得到这个＆＃34;无效的标量投影＆＃34; ERROR pig.PigServer: exception during parsing: Error during parsing. Pig script failed to parse: Invalid scalar projection: D 上的错误：

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Answer 1

试试这个， 您可以按

访问价格列

D = FILTER C BY $3 > 2.0;
or
D = FILTER C BY B::price > 2.0;

Answer 2

尝试计算关系中的任何NULL。

D = FILTER C BY price > 2.0 AND price is not null;