Examples of cascading.pipe.joiner.LeftJoin

cascading.pipe.joiner.LeftJoin
Class LeftJoin will return an {@link Iterator} that will iterate over a given {@link Joiner} and return tuples that representa left inner, right outer join of the CoGrouper internal grouped tuple collections.
Note only the farthest right tuple stream will be used as the outer join. All preceding joins to the left will be inner joins. See {@link MixedJoin} for more flexibility.
Joins perform based on the equality of the join keys. In the case of null values, Java treats two null values as equivalent. SQL does not treat null values as equal. To produce SQL like results in a given join, a new {@link java.util.Comparator} will need to be used on the joined values to prevent null fromequaling null. As a convenience, see the {@link cascading.util.NullNotEquivalentComparator} class. @see MixedJoin

    RegexFilter filter = new RegexFilter( "^\\S\\S+$" );
    tweetPipe = new Each( tweetPipe, new Fields( "token" ), filter );


    // create PIPEs for left join on the stop words
    Pipe stopPipe = new Pipe( "stop" ); // name branch
    Pipe joinPipe = new HashJoin( tweetPipe, new Fields( "token" ), stopPipe, new Fields( "stop" ), new LeftJoin() );
    joinPipe = new Each( joinPipe, new Fields( "stop" ), new RegexFilter( "^$" ) );


    joinPipe = new Retain( joinPipe, new Fields( "uid", "token" ) );


    /*

View Full Code Here

    docPipe = new Each( docPipe, scrubArguments, new ScrubFunction( scrubArguments ), Fields.RESULTS );


    // perform a left join to remove stop words, discarding the rows
    // which joined with stop words, i.e., were non-null after left join
    Pipe stopPipe = new Pipe( "stop" );
    Pipe tokenPipe = new HashJoin( docPipe, token, stopPipe, stop, new LeftJoin() );
    tokenPipe = new Each( tokenPipe, stop, new RegexFilter( "^$" ) );
    tokenPipe = new Retain( tokenPipe, fieldSelector );


    // one branch of the flow tallies the token counts for term frequency (TF)
    Pipe tfPipe = new Pipe( "TF", tokenPipe );

View Full Code Here

    results.add( new Tuple( "7", "g3", null, null ) );
    results.add( new Tuple( "7", "g4", null, null ) );
    results.add( new Tuple( "7", "g5", null, null ) );
    results.add( new Tuple( null, "h1", null, "H1" ) );


    handleJoins( "cogroupinnerouter", new LeftJoin(), results, 8, false, null );
    handleJoins( "cogroupinnerouter-resultgroup", new LeftJoin(), results, 8, true, null );
    }

View Full Code Here

    results.add( new Tuple( "7", "g3", null, null ) );
    results.add( new Tuple( "7", "g4", null, null ) );
    results.add( new Tuple( "7", "g5", null, null ) );
    results.add( new Tuple( null, "h1", null, null ) );


    handleJoins( "cogroupinnerouternull", new LeftJoin(), results, 9, false, new NullNotEquivalentComparator() );
    handleJoins( "cogroupinnerouternull-resultgroup", new LeftJoin(), results, 9, true, new NullNotEquivalentComparator() );
    }

View Full Code Here


//    fielded = new Each( fielded, new Debug( true ) );


    Pipe inner = new CoGroup( "inner", fielded, new Fields( 0 ), uniques, new Fields( "word" ), new InnerJoin() );
    Pipe outer = new CoGroup( "outer", fielded, new Fields( 0 ), uniques, new Fields( "word" ), new OuterJoin() );
    Pipe left = new CoGroup( "left", fielded, new Fields( 0 ), uniques, new Fields( "word" ), new LeftJoin() );
    Pipe right = new CoGroup( "right", fielded, new Fields( 0 ), uniques, new Fields( "word" ), new RightJoin() );


    Pipe[] heads = Pipe.pipes( uniques, fielded );
    Map<String, Tap> sources = Cascades.tapsMap( heads, Tap.taps( source, source ) );

View Full Code Here

    results.add( new Tuple( "7", "g3", null, null ) );
    results.add( new Tuple( "7", "g4", null, null ) );
    results.add( new Tuple( "7", "g5", null, null ) );
    results.add( new Tuple( null, "h1", null, "H1" ) );


    handleJoins( "joininnerouter", new LeftJoin(), results );
    }

View Full Code Here

    Tap sink = new Hfs(new TextLine(), getTestRoot() + "/output");


    Pipe lhsPipe = new Pipe("lhs");
    Pipe rhsPipe = new Pipe("rhs");


    Pipe joined = new BloomJoin(lhsPipe, new Fields("key"), rhsPipe, new Fields("key"), new Fields("key", "key2", "lhs-value", "key-copy", "key2-copy", "rhs-value"), new LeftJoin());


    CascadingUtil.get().getFlowConnector().connect(sources, sink, joined).complete();


    List<Tuple> results = TapHelper.getAllTuples(sink);
    assertEquals("All tuples from the left side should be kept", 21, results.size());

View Full Code Here

    switch( getJoinType() )
      {
      case INNER:
        return new InnerJoin();
      case LEFT:
        return new LeftJoin();
      case RIGHT:
        return new RightJoin();
      case FULL:
        return new OuterJoin();
      default:

View Full Code Here

TOP

Related Classes of cascading.pipe.joiner.LeftJoin

cascading.CoGroupFieldedPipesPlatformTest

cascading.JoinFieldedPipesPlatformTest

cascading.lingual.optiq.CascadingJoinRel

com.liveramp.cascading_ext.assembly.TestBloomJoin

impatient.Main

sample.recommender.Main

All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.