Question

我对Scala不是很好（我更像是一个R瘾君子）我希望使用Scala在两行中显示WrappedArray元素的内容（参见下面的sqlDf.show()）在spark-shell。我已经尝试了explode()功能，但无法进一步......

scala> val sqlDf = spark.sql("select t.articles.donneesComptablesArticle.taxes from  dau_temp t")
sqlDf: org.apache.spark.sql.DataFrame = [taxes: array<array<struct<baseImposition:bigint,codeCommunautaire:string,codeNatureTaxe:string,codeTaxe:string,droitCautionnable:boolean,droitPercu:boolean,imputationCreditCautionne:boolean,montantLiquidation:bigint,quotite:double,statutAi2:boolean,statutDeLiquidation:string,statutRessourcesPropres:boolean,typeTaxe:string>>>]

scala> sqlDf.show
16/12/21 15:13:21 WARN util.Utils: Truncated the string representation of a plan since it was too large. This behavior can be adjusted by setting 'spark.debug.maxToStringFields' in SparkEnv.conf.
+--------------------+
|               taxes|
+--------------------+
|[WrappedArray([12...|
+--------------------+


scala> sqlDf.printSchema
root
 |-- taxes: array (nullable = true)
 |    |-- element: array (containsNull = true)
 |    |    |-- element: struct (containsNull = true)
 |    |    |    |-- baseImposition: long (nullable = true)
 |    |    |    |-- codeCommunautaire: string (nullable = true)
 |    |    |    |-- codeNatureTaxe: string (nullable = true)
 |    |    |    |-- codeTaxe: string (nullable = true)
 |    |    |    |-- droitCautionnable: boolean (nullable = true)
 |    |    |    |-- droitPercu: boolean (nullable = true)
 |    |    |    |-- imputationCreditCautionne: boolean (nullable = true)
 |    |    |    |-- montantLiquidation: long (nullable = true)
 |    |    |    |-- quotite: double (nullable = true)
 |    |    |    |-- statutAi2: boolean (nullable = true)
 |    |    |    |-- statutDeLiquidation: string (nullable = true)
 |    |    |    |-- statutRessourcesPropres: boolean (nullable = true)
 |    |    |    |-- typeTaxe: string (nullable = true)

scala> val sqlDfTaxes = sqlDf.select(explode(sqlDf("taxes")))
sqlDfTaxes: org.apache.spark.sql.DataFrame = [col: array<struct<baseImposition:bigint,codeCommunautaire:string,codeNatureTaxe:string,codeTaxe:string,droitCautionnable:boolean,droitPercu:boolean,imputationCreditCautionne:boolean,montantLiquidation:bigint,quotite:double,statutAi2:boolean,statutDeLiquidation:string,statutRessourcesPropres:boolean,typeTaxe:string>>]

scala> sqlDfTaxes.show()
16/12/21 15:22:28 WARN util.Utils: Truncated the string representation of a plan since it was too large. This behavior can be adjusted by setting 'spark.debug.maxToStringFields' in SparkEnv.conf.
+--------------------+
|                 col|
+--------------------+
|[[12564,B00,TVA,A...|
+--------------------+

＆＃34;可读＆＃34;内容看起来像这样（这是我的GOA L：带标题的经典行x列结构显示）：

codeTaxe codeCommunautaire baseImposition quotite montantLiquidation statutDeLiquidation
A445               B00          12564    20.0               2513                   C
U165               A00          12000     4.7                564                   C
codeNatureTaxe typeTaxe statutRessourcesPropres statutAi2 imputationCreditCautionne
TVA    ADVAL                   FALSE      TRUE                     FALSE
DD    ADVAL                    TRUE     FALSE                      TRUE
droitCautionnable droitPercu
FALSE       TRUE
FALSE       TRUE

并且每行的类是（使用R package sparklyr找到它）：

<jobj[100]>
  class org.apache.spark.sql.catalyst.expressions.GenericRowWithSchema
  [12564,B00,TVA,A445,false,true,false,2513,20.0,true,C,false,ADVAL]

[[1]][[1]][[2]]
<jobj[101]>
  class org.apache.spark.sql.catalyst.expressions.GenericRowWithSchema
  [12000,A00,DD,U165,false,true,true,564,4.7,false,C,true,ADVAL]

Answer 1

你可以在每一栏上爆炸：

val flattenedtaxes = sqlDf.withColumn("codeCommunautaire",  org.apache.spark.sql.functions.explode($"taxes. codeCommunautaire"))

在此之后，您的flattenedtaxes将有2列税（所有列均按原样）新列codeCommunautaire

Spark SQL DataFrame很漂亮

1 个答案: