Pig - use ternary condition to filter based on different condition

问题

I'm trying to use PIG to filter a relation based on the current day of the week using a ternary condition but it's giving me an error that I haven't seen yet.

This is what I'm trying to do:

C = filter B by (DaysBetween(CurrentTime(),ToDate(0L)) % 7) == (long)0 ? B.interval == 'daily' : B.interval == 'weekly';

and the error that returns is:

ERROR 1200: Pig script failed to parse: NoViableAltException(84@[])

Failed to parse: Pig script failed to parse: NoViableAltException(84@[])
    at org.apache.pig.parser.QueryParserDriver.parse(QueryParserDriver.java:196)
    at org.apache.pig.PigServer$Graph.validateQuery(PigServer.java:1684)
    at org.apache.pig.PigServer$Graph.registerQuery(PigServer.java:1657)
    at org.apache.pig.PigServer.registerQuery(PigServer.java:600)
    at org.apache.pig.tools.grunt.GruntParser.processPig(GruntParser.java:1069)
    at org.apache.pig.tools.pigscript.parser.PigScriptParser.parse(PigScriptParser.java:501)
    at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:228)
    at org.apache.pig.tools.grunt.GruntParser.parseStopOnError(GruntParser.java:203)
    at org.apache.pig.tools.grunt.Grunt.run(Grunt.java:66)
    at org.apache.pig.Main.run(Main.java:542)
    at org.apache.pig.Main.main(Main.java:156)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at org.apache.hadoop.util.RunJar.main(RunJar.java:212)
Caused by: NoViableAltException(84@[])
    at org.apache.pig.parser.AstValidator.expr(AstValidator.java:8637)
    at org.apache.pig.parser.AstValidator.expr(AstValidator.java:9115)
    at org.apache.pig.parser.AstValidator.bin_expr(AstValidator.java:10531)
    at org.apache.pig.parser.AstValidator.projectable_expr(AstValidator.java:9790)
    at org.apache.pig.parser.AstValidator.var_expr(AstValidator.java:9582)
    at org.apache.pig.parser.AstValidator.expr(AstValidator.java:8985)
    at org.apache.pig.parser.AstValidator.cond(AstValidator.java:7820)
    at org.apache.pig.parser.AstValidator.filter_clause(AstValidator.java:7328)
    at org.apache.pig.parser.AstValidator.op_clause(AstValidator.java:1683)
    at org.apache.pig.parser.AstValidator.general_statement(AstValidator.java:1035)
    at org.apache.pig.parser.AstValidator.statement(AstValidator.java:499)
    at org.apache.pig.parser.AstValidator.query(AstValidator.java:373)
    at org.apache.pig.parser.QueryParserDriver.validateAst(QueryParserDriver.java:255)
    at org.apache.pig.parser.QueryParserDriver.parse(QueryParserDriver.java:183)
    ... 15 more

Does anyone have any idea why it's not working? I'm using 0.11 on my Mac.

Thanks.

EDIT: I was trying not to use UDF and I have used ternary conditions in other relations.

回答1:

I figured it out. It was just badly constructed.

This is the correct way:

C = filter B by (((DaysBetween(CurrentTime(),ToDate(0L)) % 7) == 4) ? 'daily' : 'weekly') == interval;

来源：https://stackoverflow.com/questions/27909024/pig-use-ternary-condition-to-filter-based-on-different-condition

标签

filter

apache-pig