Read a csv file that is stored in Attachment Object

Question

I have an excel/csv as an attachment related to an EmailMessage. I want to read the csv, process the data and create certain records(of custom object) based on that data. I want to understand how I can read the attachment using apex?

What I am trying to do is, get the information from an attachment.

Attachment attachmentRecord = [Select Id,Body,ContentType from Attachment  WHERE ParentId =<my EmailMessageId>];
 
System.debug('a ' +attachmentRecord.Body);
System.debug('b '+attachmentRecord.Body.toString());

When I print the body, I get the output as :

a Blob[13381]

if I convert it to string(2nd debug statement) I get an error saying :

System.StringException: BLOB is not a valid UTF-8 string

I want to understand what am I doing wrong here.

Answer 1

I was able to read a csv file from attachment record, using below apex code:

Attachment attachmentRecord = [Select Id,Body,ContentType from Attachment  WHERE ParentId = <Parent Record Id>];
String csvAsString;
String[] csvFileLines;
csvAsString = attachmentRecord.Body.toString();
csvFileLines = csvAsString.split('\n'); 
        
for(Integer i=1;i<csvFileLines.size();i++){
   string[] csvRecordData = csvFileLines[i].split(',');
   System.debug('csvFileLines '+i+' '+csvRecordData[0]);
   System.debug('csvFileLines '+i+' '+csvRecordData[1]);
   System.debug('csvFileLines '+i+' '+csvRecordData[2]);
   System.debug('csvFileLines '+i+' '+csvRecordData[3]);
 }