Apache Pig Split运算符

由 jarodhu 创建，youj 最后一次修改 2016-12-28 SPLIT 运算符用于将关系拆分为两个或多个关系。语法下面给出了 SPLIT 运算符的语法。grunt> SPLIT Relation1_name INTO Relation2_name IF (condition1), Relation2_name (condition2),例假设在HDFS目录 /pig_data/ 中有一个名为 student_details.txt 的文件，如下所示。 student_details.txt 001,Rajiv,Reddy,21,9848022337,Hyderabad002,siddarth,Battacharya,22,9848022338,Kolkata003,Rajesh,Khanna,22,9848022339,Delhi 004,Preethi,Agarwal,21,9848022330,Pune 005,Trupthi,Mohanthy,23,9848022336,Bhuwaneshwar 006,Archana,Mishra,23,9848022335,Chennai 007,Komal,Nayak,24,9848022334,trivendram 008,Bharathi,Nambiayar,24,9848022333,Chennai通过关系 student_details 将此文件加载到Pig中，如下所示。student_details = LOAD 'hdfs://localhost:9000/pig_data/student_details.txt' USING PigStorage(',') as (id:int, firstname:chararray, lastname:chararray, age:int, phone:chararray, city:chararray); 现在，让我们将关系分为两个，一个列出年龄小于23岁的员工，另一个列出年龄在22到25岁之间的员工。SPLIT student_details into student_details1 if age<23, student_details2 if (22<age and age>25);验证使用 DUMP 操作符验证关系 student_details1 和 student_details2 ，如下所示。grunt> Dump student_details1; grunt> Dump student_details2; 输出它将产生以下输出，分别显示关系 student_details1 和 student_details2 的内容。grunt> Dump student_details1; (1,Rajiv,Reddy,21,9848022337,Hyderabad) (2,siddarth,Battacharya,22,9848022338,Kolkata)(3,Rajesh,Khanna,22,9848022339,Delhi) (4,Preethi,Agarwal,21,9848022330,Pune) grunt> Dump student_details2; (5,Trupthi,Mohanthy,23,9848022336,Bhuwaneshwar) (6,Archana,Mishra,23,9848022335,Chennai) (7,Komal,Nayak,24,9848022334,trivendram) (8,Bharathi,Nambiayar,24,9848022333,Chennai)