Writing an Error message to a text field: Illegal assignment from List<Database.Error> to String

Question

I am trying to write the leadConversionResult error message to a custom field. As you can see I already write the error to the debug log. When I attempt to assign to a text field I get the following error message:

Illegal assignment from List to String

Here is my code:

if(!leadConvertResult.success){
    system.debug('The Following Error Occurred on::' + leadConvertResult.getLeadId() + 'Error is::' + leadConvertResult.getErrors());

    Lead L = new Lead(id = leadConvertResult.getLeadId());
    L.AutoConvert__c = FALSE; 
    L.Possible_Duplicate__c =TRUE;
    L.Conversion_error_message__c =leadConvertResult.getErrors();

    if(L.Ignore_Duplicate_error__c == FALSE){
        DuplicateLead.add(L);
    }
}

Answer 1

As the error says, you're trying to convert a list of objects into a plain string. You need to convert the errors into a plain string:

String[] messages = new String[0];
for(Database.Error error: leadConvertResult.getErrors()) {
    messages.add(error.getMessage());
}
L.Conversion_Error_Message__c = String.join(messages, '\n');