如何从字符串列中提取数字？

我的要求是从列中的评论列中检索订单号comment并且总是开始于R。订单号应作为新列添加到表中。

输入数据：

code,id,mode,location,status,comment 
AS-SD,101,Airways,hyderabad,D,order got delayed R1657
FY-YT,102,Airways,Delhi,ND,R7856 package damaged
TY-OP,103,Airways,Pune,D,Order number R5463 not received

预期输出：

AS-SD,101,Airways,hyderabad,D,order got delayed R1657,R1657
FY-YT,102,Airways,Delhi,ND,R7856 package damaged,R7856 
TY-OP,103,Airways,Pune,D,Order number R5463 not received,R5463 

我在spark-sql中尝试过，我使用的查询如下：

val r = sqlContext.sql("select substring(comment, PatIndex('%[0-9]%',comment, length(comment))) as number from A")

但是，我收到以下错误：

org.apache.spark.sql.AnalysisException: undefined function PatIndex; line 0 pos 0

您可以使用regexp_extract其定义为：

def regexp_extract(e: Column, exp: String, groupIdx: Int): Column

(R\\d{4}) means R随后是 4 位数字。您可以使用有效的正则表达式轻松适应任何其他情况

df.withColumn("orderId", regexp_extract($"comment", "(R\\d{4})" , 1 )).show

+-----+---+-------+---------+------+--------------------+-------+
| code| id|   mode| location|status|             comment|orderId|
+-----+---+-------+---------+------+--------------------+-------+
|AS-SD|101|Airways|hyderabad|     D|order got delayed...|  R1657|
|FY-YT|102|Airways|    Delhi|    ND|R7856 package dam...|  R7856|
|TY-OP|103|Airways|     Pune|     D|Order number R546...|  R5463|
+-----+---+-------+---------+------+--------------------+-------+