The only way to get it to work is to load a second copy. On Thu, Jul 19, 2012 at 7:46 PM, Russell Jurney <[email protected]>wrote:
> Note: this works if I LOAD a new, 2nd relation and do the join. > > On Thu, Jul 19, 2012 at 7:34 PM, Russell Jurney <[email protected] > >wrote: > > > I have a problem where I can't join a relation to itself on a different > > field. > > > > describe pairs > > pairs: {from: chararray,to: chararray,message_id: chararray,in_reply_to: > > chararray} > > > > pairs2 = pairs; > > > > with_reply = join pairs by in_reply_to, pairs2 by message_id; > > > > > > I get this error: > > > > 2012-07-19 19:31:16,927 [main] ERROR org.apache.pig.tools.grunt.Grunt - > > ERROR 1200: Pig script failed to parse: > > <line 20, column 6> pig script failed to validate: > > org.apache.pig.impl.logicalLayer.FrontendException: ERROR 2225: > Projection > > with nothing to reference! > > 2012-07-19 19:31:16,928 [main] ERROR org.apache.pig.tools.grunt.Grunt - > > Failed to parse: Pig script failed to parse: > > <line 20, column 6> pig script failed to validate: > > org.apache.pig.impl.logicalLayer.FrontendException: ERROR 2225: > Projection > > with nothing to reference! > > at > > org.apache.pig.parser.QueryParserDriver.parse(QueryParserDriver.java:182) > > at org.apache.pig.PigServer$Graph.validateQuery(PigServer.java:1565) > > at org.apache.pig.PigServer$Graph.registerQuery(PigServer.java:1538) > > at org.apache.pig.PigServer.registerQuery(PigServer.java:540) > > at > org.apache.pig.tools.grunt.GruntParser.processPig(GruntParser.java:970) > > at > > > org.apache.pig.tools.pigscript.parser.PigScriptParser.parse(PigScriptParser.java:386) > > at > > > org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:189) > > at > > > org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:165) > > at org.apache.pig.tools.grunt.Grunt.run(Grunt.java:69) > > at org.apache.pig.Main.run(Main.java:490) > > at org.apache.pig.Main.main(Main.java:111) > > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) > > at > > > sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) > > at > > > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) > > at java.lang.reflect.Method.invoke(Method.java:597) > > at org.apache.hadoop.util.RunJar.main(RunJar.java:156) > > Caused by: > > <line 20, column 6> pig script failed to validate: > > org.apache.pig.impl.logicalLayer.FrontendException: ERROR 2225: > Projection > > with nothing to reference! > > at > > > org.apache.pig.parser.LogicalPlanBuilder.buildJoinOp(LogicalPlanBuilder.java:363) > > at > > > org.apache.pig.parser.LogicalPlanGenerator.join_clause(LogicalPlanGenerator.java:11354) > > at > > > org.apache.pig.parser.LogicalPlanGenerator.op_clause(LogicalPlanGenerator.java:1489) > > at > > > org.apache.pig.parser.LogicalPlanGenerator.general_statement(LogicalPlanGenerator.java:789) > > at > > > org.apache.pig.parser.LogicalPlanGenerator.statement(LogicalPlanGenerator.java:507) > > at > > > org.apache.pig.parser.LogicalPlanGenerator.query(LogicalPlanGenerator.java:382) > > at > > org.apache.pig.parser.QueryParserDriver.parse(QueryParserDriver.java:175) > > ... 15 more > > > > > > What am I to do? > > -- > > Russell Jurney twitter.com/rjurney [email protected]. > > com > > > > > > -- > Russell Jurney twitter.com/rjurney [email protected] > datasyndrome.com > -- Robert Yerex Data Scientist Civitas Learning www.civitaslearning.com
