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From Shmuel Blitz <shmuel.bl...@similarweb.com>
Subject Re: Re: the issue about the + in column,can we support the string please?
Date Mon, 26 Mar 2018 09:17:14 GMT
I agree.

Just pointed out the option, in case you missed it.

Cheers,
Shmuel

On Mon, Mar 26, 2018 at 10:57 AM, 1427357147@qq.com <1427357147@qq.com>
wrote:

> Hi,
>
> Using concat is one of the way.
> But the + is more intuitive and easy to understand.
>
> ------------------------------
> 1427357147@qq.com
>
>
> *From:* Shmuel Blitz <shmuel.blitz@similarweb.com>
> *Date:* 2018-03-26 15:31
> *To:* 1427357147@qq.com
> *CC:* spark?users <user@spark.apache.org>; dev <dev@spark.apache.org>
> *Subject:* Re: the issue about the + in column,can we support the string
> please?
> Hi,
>
> you can get the same with:
>
> import org.apache.spark.sql.functions._
> import sqlContext.implicits._
> import org.apache.spark.sql.types.{IntegerType, StringType, StructField,
> StructType}
>
> val schema = StructType(Array(StructField("name", StringType),
>                                 StructField("age", IntegerType) ))
>
> val lst = List(Row("Shmuel", 13), Row("Blitz", 23))
> val rdd = sc.parallelize(lst)
>
> val df = sqlContext.createDataFrame(rdd,schema)
>
> df.withColumn("newName", concat($"name" ,  lit("abc"))  ).show()
>
> On Mon, Mar 26, 2018 at 6:36 AM, 1427357147@qq.com <1427357147@qq.com>
> wrote:
>
>> Hi  all,
>>
>> I have a table like below:
>>
>> +---+---------+-----------+
>> | id|     name|sharding_id|
>> +---+---------+-----------+
>> |  1|leader us|      10000|
>> |  3|    mycat|      10000|
>> +---+---------+-----------+
>>
>> My schema is :
>> root
>>  |-- id: integer (nullable = false)
>>  |-- name: string (nullable = true)
>>  |-- sharding_id: integer (nullable = false)
>>
>> I want add a new column named newName. The new column is based on "name"
>> and append "abc" after it. My code looks like:
>>
>> stud_scoreDF.withColumn("newName", stud_scoreDF.col("name") +  "abc"  ).show()
>>
>> When I run the code, I got the reslult:
>> +---+---------+-----------+-------+
>> | id|     name|sharding_id|newName|
>> +---+---------+-----------+-------+
>> |  1|leader us|      10000|   null|
>> |  3|    mycat|      10000|   null|
>> +---+---------+-----------+-------+
>>
>>
>> I checked the code, the key code is  in arithmetic.scala. line 165.
>> It looks like:
>>
>> override def doGenCode(ctx: CodegenContext, ev: ExprCode): ExprCode = dataType match
{
>>   case dt: DecimalType =>
>>     defineCodeGen(ctx, ev, (eval1, eval2) => s"$eval1.$$plus($eval2)")
>>   case ByteType | ShortType =>
>>     defineCodeGen(ctx, ev,
>>       (eval1, eval2) => s"(${ctx.javaType(dataType)})($eval1 $symbol $eval2)")
>>   case CalendarIntervalType =>
>>     defineCodeGen(ctx, ev, (eval1, eval2) => s"$eval1.add($eval2)")
>>   case _ =>
>>     defineCodeGen(ctx, ev, (eval1, eval2) => s"$eval1 $symbol $eval2")
>> }
>>
>>
>> My issue is:
>> Can we add case StringType in this class to support string append please?
>>
>>
>>
>> ------------------------------
>> 1427357147@qq.com
>>
>
>
>
> --
> Shmuel Blitz
> Big Data Developer
> Email: shmuel.blitz@similarweb.com
> www.similarweb.com
> <https://www.facebook.com/SimilarWeb/>
> <https://www.linkedin.com/company/429838/>
> <https://twitter.com/similarweb>
>
>


-- 
Shmuel Blitz
Big Data Developer
Email: shmuel.blitz@similarweb.com
www.similarweb.com
<https://www.facebook.com/SimilarWeb/>
<https://www.linkedin.com/company/429838/> <https://twitter.com/similarweb>

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