spark sql 自定義udf函數

import org.apache.spark.sql.functions._

def compare(value_missing: String, value: String): Boolean = {
    var flag = false
    if (value_missing.length == value.length) {
      flag = value_missing.zip(value).forall {
        case ('*', c2) => true
        case (c1, '*') => true
        case (c1, c2) => c1 == c2
      }
    }
    flag
  }

val udf_compare = udf(compare(_: String, _: String): Boolean)

df.withColumn("flag", udf_compare($"mobile_missing", $"mobile"))