Hi Sid, Emilio,

It was a mistake on my part. I was not setting the holder.start and holder.end 
values inside the NullableVarCharHolder, which was causing the issue. It works 


-----Original Message-----
From: Atul Dambalkar 
Sent: Wednesday, April 11, 2018 5:18 PM
To: dev@arrow.apache.org
Subject: RE: Correct way to set NULL values in VarCharVector (Java API)?

Hi Sid, Emilio,

Need some more help. Here is how I am using the NullableVarCharHolder -

        String value = "some text string";
        NullableVarCharHolder holder = new NullableVarCharHolder();
        holder.isSet = 1;
        byte[] bytes = value.getBytes(StandardCharsets.UTF_8);
        holder.buffer = varcharVector.getAllocator().buffer(bytes.length);
        holder.buffer.setBytes(0, bytes, 0, bytes.length);
        varcharVector.setSafe(index, holder);
        varcharVector.setValueCount(index + 1);

When I try to access the byte[] from VarCharVector as varcharVector.get(index) 
it's returning me null array. If I access the holder.buffer value before 
putting it in the VarCharVector, I can access the correct byte[], but after I 
set it inside the vector, I am getting it as null. Is this correct usage for 
the API? 


-----Original Message-----
From: Siddharth Teotia [mailto:siddha...@dremio.com]
Sent: Wednesday, April 11, 2018 10:27 AM
To: dev@arrow.apache.org
Subject: Re: Correct way to set NULL values in VarCharVector (Java API)?

Another option is to use the set() API that allows you to indicate whether the 
value is NULL or not using an isSet parameter (0 for NULL, 1 otherwise). This 
is similar to holder based APIs where you need to indicate in holder.isSet 
whether value is NULL or not.



On Wed, Apr 11, 2018 at 6:14 AM, Emilio Lahr-Vivaz <elahrvi...@ccri.com>

> Hi Atul,
> You should be able to use the overloaded 'set' method that takes a
> NullableVarCharHolder:
> https://github.com/apache/arrow/blob/master/java/vector/src/
> main/java/org/apache/arrow/vector/VarCharVector.java#L237
> Thanks,
> Emilio
> On 04/10/2018 05:23 PM, Atul Dambalkar wrote:
>> Hi,
>> I wanted to know what's the best way to handle NULL string values 
>> coming from a relational database. I am trying to set the string 
>> values in Java API - VarCharVector. Like few other Arrow Vectors 
>> (TimeStampVector, TimeMilliVector), the VarCharVector doesn't have a 
>> way to set a NULL value as one of the elements. Can someone advise 
>> what's the correct mechanism to store NULL values in this case.
>> Regards,
>> -Atul

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