Question

我的一个专栏（名为Product）被定义为Chararray，它有三个值：OT，AT和HP。我想创建一个新列并将其转换为整数：

OT = 1
AT = 2
HP = 3

为此我创建了一个foreach语句：

REGISTER '/usr/lib/pig/piggybank.jar';

File = load '/user/cloudera/file.csv'  
    USING org.apache.pig.piggybank.storage.CSVExcelStorage(',')
      as (ID:Long, 
          Chain:Int,
          Dept:Int,
          Product_Measure:Chararray,
          Price:Double);


Values = FOREACH File Generate
                            ID,
                                            Chain,
                                            Dept,
                                            ((Chararray)Product_Measure=='OT'?'1':(Chararray)Product_Measure=='AT'?'2':(Chararray)Product_Measure=='HP'?'3':'0') as Product_Measure,
                                            (Price<0.1?0:Price) as Price;

Filter_Values = FILTER Values BY  Price > 0;

DUMP  Filter_Values;

如果删除thrid行它工作正常，所以我认为当我尝试在int中转换chararray时问题出现了。

任何人都可以帮助我吗？

谢谢！

Answer 1

Values = FOREACH Source Generate
                       ID,
                       Date,
                      ((Chararray)Product == 'OT' ? (int)1 :  (Chararray)Product_Measure == 'AT' ? (int)2 : (Chararray)Product_Measure == 'HP' ? (int)3 : 0) as Product_Value,
                     (Quantity<0?0:Quantity) as Quantity,
                     (Price<0.1?0:Price) as Price;

或者如果你想要NULL那么

 Values = FOREACH Source Generate
                           ID,
                           Date,
                          ((Chararray)Product == 'OT' ? '1' :  (Chararray)Product_Measure == 'AT' ? '2' : (Chararray)Product_Measure == 'HP' ? '3' : 'NULL') as Product_Value,
                         (Quantity<0?0:Quantity) as Quantity,
                         (Price<0.1?0:Price) as Price;

你需要在你的猪脚本中进行两次修改。第1代=刚刚放== 如果您想要null值，请将其转换为chararray，否则所有替换值均为int

Apache PIG - 根据另一个值创建一个新列

1 个答案: