I would like some help on a trigger and apex class i am working on. Below is the code.  It occurs when i try to submit the survey.

ERROR CODE:
System.DmlException: Insert failed. First exception on row 0; first error: CANNOT_INSERT_UPDATE_ACTIVATE_ENTITY, Trigger_SurveyAfterInsert: execution of AfterInsert caused by: System.QueryException: List has no rows for assignment to SObject Trigger.Trigger_SurveyAfterInsert: line 8, column 1: []
Error is in expression '{!insertSurvey}' in component <apex:commandButton> in page vf_sales_survey: Class.VFController_survey_opps.insertSurvey: line 44, column 1

Class.VFController_survey_opps.insertSurvey: line 44, column 1



TRIGGER:
trigger Trigger_SalesSurveyAfterInsert on Survey__c(after insert) {

   
     for(Survey__c event: System.Trigger.New){
        List<Survey__c> lobjects;
        string name;
        lobjects = [select Id, Opportunity__c, OppId__c from Survey__c where Id=:event.Id];
        if(lobjects.size() == 1){
            Survey__c srv = lobjects[0];
            Opportunity opp = [select Id, AccountId from Opportunity where Id=:srv.Opportunity__c  ];
            srv.Opportunity__c = opp.Id ;
            srv.Account__c = opp.AccountId ;
           
            update srv;
        }
    }


}


APEX CODE:
public with sharing class VFController_survey_opps {
public String oppId {get;set;}

        public Integer q1{get;set;}
        public Integer q2{get;set;}
        public Integer q3{get;set;}
        public Integer q4{get;set;}
        public Integer q5{get;set;}
        public Integer q6{get;set;}
        public Integer q7{get;set;}
        public Integer q8{get;set;}
        public Integer q9{get;set;}
        public Integer q10{get;set;}
        public Integer q11{get;set;}
        public Integer q12{get;set;}
        public Integer q13{get;set;}
        public Integer q14{get;set;}
        public String comments{get;set;}
       
        public VFController_survey_opps()
        {
                oppId = ApexPages.currentPage().getParameters().get('oppId');
        }
       
        public PageReference insertSurvey(){
                Survey__c sv = new Survey__c();
             
                sv.OppId__c = oppId;
                sv.Question_1__c = q1;
                sv.Question_2__c = q2;
                sv.Question_3__c = q3;
                sv.Question_4__c = q4;
                sv.Question_5__c = q5;
                sv.Question_6__c = q6;
                sv.Question_7__c = q7;
                sv.Question_8__c = q8;
                sv.Question_9__c = q9;
                sv.Question_10__c = q10;
                sv.Question_11__c = q11;
                sv.Question_12__c = q12;
                sv.Question_13__c = q13;
                sv.Question_14__c = q14;
                sv.Comments__c = comments;
                insert sv;
               
                //put a redirect to a new thank you vf page
               
                PageReference cPage = new PageReference('/apex/vr_survey_thank_you');
        cPage.setRedirect(true);
        return cPage;
       
                return null;
        }
       
         public List<SelectOption> getItems() {
        List<SelectOption> options = new List<SelectOption>();
        options.add(new SelectOption('5','Excellent'));
        options.add(new SelectOption('4','Good'));
        options.add(new SelectOption('3','Average'));
        options.add(new SelectOption('2','Fair'));
        options.add(new SelectOption('1','Poor'));
        options.add(new SelectOption('0','NA'));
       
       
        return options;
    }
   
    public List<SelectOption> getItems2() {
        List<SelectOption> options = new List<SelectOption>();
        options.add(new SelectOption('5','Excellent'));
        options.add(new SelectOption('4','Good'));
        options.add(new SelectOption('3','Average'));
        options.add(new SelectOption('2','Fair'));
        options.add(new SelectOption('1','Poor'));
        options.add(new SelectOption('0','NA'));
       
        return options;
    }

 
}