Hi my dear friends,
Usually when i face a problem i search before asking here, but i'm facing a problem where i couldn't find a solution for it by search.
i'm using Connection to a database at Presto,
Connection has been done successfully but the issue is in writing a query with Single and double Quotes , Please help me in these 10's of errors 


the code used is ;
library(DBI)
library(dplyr)
library(RPresto)
res = dbSendQuery(con, " select RESPONDENT as Respondent,RESPONSE_DATE as Date,
MAX(CASE
WHEN QUESTION_ID = '18' AND RESPONSE_ID ='5' THEN 'Very Satisfied'
WHEN QUESTION_ID = '18' AND RESPONSE_ID ='4' THEN 'Satisfied'
WHEN QUESTION_ID = '18' AND RESPONSE_ID ='3' THEN 'Neutral'
WHEN QUESTION_ID = '18' AND RESPONSE_ID ='2' THEN 'Dissatisfied'
WHEN QUESTION_ID = '18' AND RESPONSE_ID ='1' THEN 'Very Dissatisfied' ELSE NULL END) AS "How was our service looks based on your last meal?"
from surveytable
group by 1,2")
Sample from Errors appeared
Error: unexpected numeric constant in:
" WHEN QUESTION_ID = '18' AND RESPONSE_ID ='2' THEN 'Dissatisfied' **
** WHEN QUESTION_ID = '18' AND RESPONSE_ID ='1' THEN 'Very Dissatisfied' ELSE NULL END) AS "7."
I Appreciate your unlimited support my freinds 