Question

我的数据框的列名称包含＆＃34;。＆＃34; 我想过滤列以获取包含＆＃34;。＆＃34;的列名称。然后选择它。任何帮助将不胜感激。这是数据集

//dataset
    time.1,col.1,col.2,col.3
    2015-12-06 12:40:00,2,2,3
    2015-12-07 12:41:35,3,3,4

val spark = SparkSession.builder.master("local").appName("my-spark-app").getOrCreate()
    val df1 = spark.read.option("inferSchema", "true").option("header", "true").csv("C:/Users/mhattabi/Desktop/dataTestCsvFile/dataTest2.txt")
    val columnContainingdots=df1.schema.fieldNames.filter(p=>p.contains('.'))
    df1.select(columnContainingdots)

Answer 1

在列名中包含点将要求您用“`”字符括起名称。请参阅以下代码，这应该符合您的目的。

val columnContainingDots = df1.schema.fieldNames.collect({
  // since the column names has "." character, we must enclose the column names with "`", otherwise dataframe select will cause exception
  case column if column.contains('.') => s"`${column}`"
})

df1.select(columnContainingDots.head, columnContainingDots.tail:_*)

对包含点的列的Makiing sql请求

1 个答案: