How to extract number from string column?

Question

My requirement is to retrieve the order number from the comment column which is in a column comment and always starts with R. The order number should be added as a new column to the table.

Input data:

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

Expected output:

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 

I have tried it in spark-sql, the query I am using is given below:

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

However, I'm getting the following error:

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

Answer 1

You can use regexp_extract which has the definition :

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

(R\\d{4}) means R followed by 4 digits. You can easily accommodate any other case by using a valid regex

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|
+-----+---+-------+---------+------+--------------------+-------+