Custom button on Opportunity to clone opportunity with its related List (object)
Create a new Detail Page Button on the Opportunity object. Set Behavior to Execute JavaScript and Content Source to OnClick JavaScript Paste the Below snippet of code in the window {!REQUIRESCRIPT("/soap/ajax/39.0/connection.js")} {!REQUIRESCRIPT("/soap/ajax/39.0/apex.js")} var retStr; retStr = sforce.apex.execute(" CloneOpportunitywithRelatedObject "," cloneOpportunity ", {oppId:"{!Opportunity.Id}"}); location.replace('/' + retStr); Create a new Apex class and paste the below snippet of code global class CloneOpportunitywithRelatedObject { webservice static Id cloneOpportunity (Id oppId) // pass parameters { List < Related_Object__C > relatedList = new List < Related_Object__C > (); // query all the fields you need to clone Opportunity opp = [SELECT ID, CloseDate, StageName, Type, Name FROM Opportunity WHERE Id =: oppId