Copy a Field

In this example, you will learn how you can use DataPipeline to copy the data from one column of a CSV file to another existing or new column. It allows users to easily duplicate or transfer data within the CSV file, providing flexibility in data manipulation and organization.

Input CSV file

Account,LastName,FirstName,Balance,CreditLimit,AccountCreated,Rating
101,Reeves,Keanu,9315.45,10000.00,1/17/1998,A
312,Butler,Gerard,90.00,1000.00,8/6/2003,B
868,Hewitt,Jennifer Love,0,17000.00,5/25/1985,B
761,Pinkett-Smith,Jada,49654.87,100000.00,12/5/2006,A
317,Murray,Bill,789.65,5000.00,2/5/2007,C

Java Code Listing

package com.northconcepts.datapipeline.examples.cookbook;

import java.io.File;

import com.northconcepts.datapipeline.core.DataReader;
import com.northconcepts.datapipeline.core.StreamWriter;
import com.northconcepts.datapipeline.csv.CSVReader;
import com.northconcepts.datapipeline.job.Job;
import com.northconcepts.datapipeline.transform.CopyField;
import com.northconcepts.datapipeline.transform.TransformingReader;

public class CopyAField {
    
    public static void main(String[] args) throws Throwable {
        DataReader reader = new CSVReader(new File("example/data/input/credit-balance-01.csv"))
            .setFieldNamesInFirstRow(true);
        
        reader = new TransformingReader(reader)
                .add(new CopyField("Rating", "Score", false));   // copy 'Rating' to 'Score'; do not overwrite
        
        Job.run(reader, new StreamWriter(System.out));
    }
    
}

Code walkthrough

1. CSVReader is created corresponding to the input file credit-balance-01.csv.
2. The CSVReader.setFieldNamesInFirstRow(true) method is invoked to specify that the names specified in the first row should be used as field names.
3. A TransformingReader is created to apply one or more transformations to the incoming data sequentially.
4. CopyField object accepts String sourceFieldName, targetFieldName  and boolean overwrite arguments. In the given example, data in the "Rating" field is being copied to a new "Score" field without overwriting.
5.  Data is transferred from the reader to the StreamWriter(System.out) via Job.run() method.

Output

-----------------------------------------------
0 - Record {
    0:[Account]:STRING=[101]:String
    1:[LastName]:STRING=[Reeves]:String
    2:[FirstName]:STRING=[Keanu]:String
    3:[Balance]:STRING=[9315.45]:String
    4:[CreditLimit]:STRING=[10000.00]:String
    5:[AccountCreated]:STRING=[1/17/1998]:String
    6:[Rating]:STRING=[A]:String
    7:[Score]:STRING=[A]:String
}

-----------------------------------------------
1 - Record {
    0:[Account]:STRING=[312]:String
    1:[LastName]:STRING=[Butler]:String
    2:[FirstName]:STRING=[Gerard]:String
    3:[Balance]:STRING=[90.00]:String
    4:[CreditLimit]:STRING=[1000.00]:String
    5:[AccountCreated]:STRING=[8/6/2003]:String
    6:[Rating]:STRING=[B]:String
    7:[Score]:STRING=[B]:String
}

-----------------------------------------------
2 - Record {
    0:[Account]:STRING=[868]:String
    1:[LastName]:STRING=[Hewitt]:String
    2:[FirstName]:STRING=[Jennifer Love]:String
    3:[Balance]:STRING=[0]:String
    4:[CreditLimit]:STRING=[17000.00]:String
    5:[AccountCreated]:STRING=[5/25/1985]:String
    6:[Rating]:STRING=[B]:String
    7:[Score]:STRING=[B]:String
}

-----------------------------------------------
3 - Record {
    0:[Account]:STRING=[761]:String
    1:[LastName]:STRING=[Pinkett-Smith]:String
    2:[FirstName]:STRING=[Jada]:String
    3:[Balance]:STRING=[49654.87]:String
    4:[CreditLimit]:STRING=[100000.00]:String
    5:[AccountCreated]:STRING=[12/5/2006]:String
    6:[Rating]:STRING=[A]:String
    7:[Score]:STRING=[A]:String
}

-----------------------------------------------
4 - Record {
    0:[Account]:STRING=[317]:String
    1:[LastName]:STRING=[Murray]:String
    2:[FirstName]:STRING=[Bill]:String
    3:[Balance]:STRING=[789.65]:String
    4:[CreditLimit]:STRING=[5000.00]:String
    5:[AccountCreated]:STRING=[2/5/2007]:String
    6:[Rating]:STRING=[C]:String
    7:[Score]:STRING=[C]:String
}

-----------------------------------------------
5 records