Apache Pig - Split Operator

SPLIT 运算符用于将关系拆分为两个或更多关系.

语法

如下所示是 SPLIT 运算符的语法.

grunt> SPLIT Relation1_name INTO Relation2_name IF (condition1), Relation2_name (condition2),

示例

假设我们有一个文件在HDFS目录/pig_data/中命名为 student_details.txt ，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

我们已将此文件加载到Pig中，关系名称为 student_details ，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

验证关系 student_details1 和 student_details2 使用 DUMP 运算符，如下所示.

grunt> Dump student_details1;  grunt> Dump student_details2;

输出

它将产生以下输出，显示关系的内容 student_details1 和 student_details2 .

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)