FAQ
All,

I have what should be a simple problem. I have 2 tuples that are chararrays t1, t2 and want to do a comparision. using

x = FILTER y BY (t1 == t2);

results in zero (0) records.

x = FILTER y BY (t1 != t2);

is zero records. And

x = FILTER y BY (t1 matches t2);

is an error. Ideal would be a StrComp(t1, t2) filter func.

Is there a UDF for that?

Cheers,

## Search Discussions

•  at Aug 18, 2010 at 10:57 pm ⇧
Dave,
Can you provide some sample data? A tuple can't be a chararray (but it can
contain one), so I want to make sure I understand what the data you are
working with looks like.

-Dmitriy
On Wed, Aug 18, 2010 at 3:29 PM, Dave Wellman wrote:

All,

I have what should be a simple problem. I have 2 tuples that are
chararrays t1, t2 and want to do a comparision. using

x = FILTER y BY (t1 == t2);

results in zero (0) records.

x = FILTER y BY (t1 != t2);

is zero records. And

x = FILTER y BY (t1 matches t2);

is an error. Ideal would be a StrComp(t1, t2) filter func.

Is there a UDF for that?

Cheers,
•  at Aug 19, 2010 at 12:26 am ⇧
Because I wasn't able to find one I tossed this UDF into the mix.

public class StrComp extends EvalFunc<Integer> {

@Override
public Integer exec(Tuple arg0) throws IOException {
// should have 2 tuples.
if (arg0.size() != 2) {
throw new IOException("Dude where's my tuples?");
}

return arg0.get(0).toString().compareTo(arg0.get(1).toString());
}
}

And the pig calls:

x = FILTER y BY StrComp(a, b) == 0;

or

x = FILTER y BY StrComp(a, b) != 0;

The tuples a and b are chararray. My solution "works" but a nice standard piggy bank udfs would be better.

On Aug 18, 2010, at 4:56 PM, Dmitriy Ryaboy wrote:

Dave,
Can you provide some sample data? A tuple can't be a chararray (but it can
contain one), so I want to make sure I understand what the data you are
working with looks like.

-Dmitriy
On Wed, Aug 18, 2010 at 3:29 PM, Dave Wellman wrote:

All,

I have what should be a simple problem. I have 2 tuples that are
chararrays t1, t2 and want to do a comparision. using

x = FILTER y BY (t1 == t2);

results in zero (0) records.

x = FILTER y BY (t1 != t2);

is zero records. And

x = FILTER y BY (t1 matches t2);

is an error. Ideal would be a StrComp(t1, t2) filter func.

Is there a UDF for that?

Cheers,
•  at Aug 20, 2010 at 12:49 am ⇧
Something strange is happening with your data. Can you provide an example?

I just tried this, with both Pig 6 and Pig 8 (trunk):

grunt> strings = load 'tmp/strings.txt' as (a:chararray, b:chararray);
grunt> dump strings;
(foo,bar)
(foo,baz)
(foo,foo)
(bar,bar)
grunt> x = filter strings by a == b;
grunt> dump x;
(foo,foo)
(bar,bar)
grunt> x = filter strings by a != b;
grunt> dump x
(foo,bar)
(foo,baz)

On Wed, Aug 18, 2010 at 4:22 PM, Dave Wellman wrote:

Because I wasn't able to find one I tossed this UDF into the mix.

public class StrComp extends EvalFunc<Integer> {

@Override
public Integer exec(Tuple arg0) throws IOException {
// should have 2 tuples.
if (arg0.size() != 2) {
throw new IOException("Dude where's my tuples?");
}

return
arg0.get(0).toString().compareTo(arg0.get(1).toString());
}
}

And the pig calls:

x = FILTER y BY StrComp(a, b) == 0;

or

x = FILTER y BY StrComp(a, b) != 0;

The tuples a and b are chararray. My solution "works" but a nice standard
piggy bank udfs would be better.

On Aug 18, 2010, at 4:56 PM, Dmitriy Ryaboy wrote:

Dave,
Can you provide some sample data? A tuple can't be a chararray (but it can
contain one), so I want to make sure I understand what the data you are
working with looks like.

-Dmitriy
On Wed, Aug 18, 2010 at 3:29 PM, Dave Wellman wrote:

All,

I have what should be a simple problem. I have 2 tuples that are
chararrays t1, t2 and want to do a comparision. using

x = FILTER y BY (t1 == t2);

results in zero (0) records.

x = FILTER y BY (t1 != t2);

is zero records. And

x = FILTER y BY (t1 matches t2);

is an error. Ideal would be a StrComp(t1, t2) filter func.

Is there a UDF for that?

Cheers,

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 group user categories pig, hadoop posted Aug 18, '10 at 10:38p active Aug 20, '10 at 12:49a posts 4 users 2 website pig.apache.org

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