我的输入记录：

4000001,Kristina,Chung,55,Pilot
4000002,Paige,Chen,74,Teacher
4000003,Sherri,Melton,34,Firefighter
4000004,Gretchen,Hill,66,Computer hardware engineer
4000005,Karen,Puckett,74,Lawyer
4000006,Patrick,Song,42,Veterinarian
4000007,Elsie,Hamilton,43,Pilot
4000008,Hazel,Bender,63,Carpenter
4000009,Malcolm,Wagner,39,Artist
4000010,Dolores,McLaughlin,60,Writer
4000011,Francis,McNamara,47,Therapist
4000012,Sandy,Raynor,26,Writer
4000013,Marion,Moon,41,Carpenter
4000014,Beth,Woodard,65,
4000015,Julia,Desai,49,Musician
4000016,Jerome,Wallace,52,Pharmacist
4000017,Neal,Lawrence,72,Computer support specialist
4000018,Jean,Griffin,45,Childcare worker
4000019,Kristine,Dougherty,63,Financial analyst
4000020,Crystal,Powers,67,Engineering technician
4000021,Alex,May,39,Environmental scientist
4000022,Eric,Steele,66,Doctor
4000023,Wesley,Teague,42,Carpenter
4000024,Franklin,Vick,28,Dancer
4000025,Claire,Gallagher,42,Musician

清管器命令：

cust = load '/input/custs' using PigStorage(',') as (custid:chararray, firstname:chararray, lastname:chararray,age:long,profession:chararray);

工作正常

groupbyprofession = group cust by profession;

工作正常

countbyprofession = foreach groupbyprofession generate group, COUNT(cust);
dump countbyprofession;

显示错误：error org.apache.pig.tools.grunt.grunt-error 1000:解析期间出错。标量只能用于投影。