Migrate Attachments from one Salesforce to another Salesforce Org

Through this blog, I will be sharing simple apex code through which you can fetch the attachment from another org and save it in your current org as attachments. This process includes 2 API calls as mentioned below:

• First API call to fetch attachment details like attachment name etc.
• Second API call to fetch attachment body.  Attachment body will be returned in binary format so get the response body as blob and then use it to insert attachment in your current org.

Below is code snippet which you can use to migrate attachment:

In order to test above script, run below mentioned script in developer console:

string sourceOrgUrlAttachmentId='00P0K00001ZvWpe';

string sourceOrgURL='https://sk02-dev-ed.my.salesforce.com';

string access_Token='0XXXXXXXXXXXXXXXXXX8ADac';

string currOrgParentRecid='00190000004Awot';

string result=SK_AttachmentMigrationHelper.findAttachmentDetails(sourceOrgUrlAttachmentId,sourceOrgURL,access_Token,currOrgParentRecid);

system.debug('***attachment Id after migration:'+result);

Instead of access_token, you can also use sessiond of user from source Org.

Refer below URL to understand how to get access token from salesforce:

ACCESS TOKEN USING OAUTH 2.0 IN SALESFORCE

How to get all attachments related to parent record Id

Specify endpoint URL as mentioned below while performing callout:

string parentRecId='001xxxxxxxxxxx';

EndPointURL= EndPointURL +'/services/data/v45.0/query/?q=select+id,parentid,ContentType,+name+from+attachment+where+parentid=\''+parentRecId+'\'';

How to migrate bulk attachments from one salesforce org to another

Before migrating the attachments, you will be migrating the parent records from source org to target org. So while migrating store the source org record Id in new custom field in target org.

Now write a batch class in target org and take references from above code to process records one by one. Execute the batch class with 1 batch size.

Hope this will help!!