Declare varible not working in Execute SQL task

Hi Experts,

I am trying to use a declare variable in the Execute SQL Task queryfield in SSIS and it is not returning me any resultsets. My query returns "PriorMonth" and "CurrentMonth" and I have this working in SSMS but the PriorMonth changing every quarter(according to the business reqt). Now the problem I am facing is if I keep that same query in "Execute SQL task" i get errors like "error while assigning value to the variable." On the result set in the General tab I have set it to Single Row and on the result set tab, I have two variable name which is as prior_month and current_month and the result set name is set as 0 and1. I would really appreciate your helpregarding this. Below is my query:


Declare @Current_Month VARCHAR(55);

DECLARE @Prior_Month_1 VARCHAR(20);
DECLARE @Prior_Month_2 VARCHAR(20);
DECLARE @Prior_Month_3 VARCHAR(20);
DECLARE @Prior_Month_4 VARCHAR(20);
DECLARE @Prior_month  varchar(20);

set @Prior_Month_1 =''''+Convert(Varchar,dateadd(QUARTER, -4,DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,GETDATE())+1,0))),101)+''''
set @Prior_Month_2 =''''+Convert(Varchar,dateadd(QUARTER, -3,DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,GETDATE())+1,0))),101)+''''
set @Prior_Month_3 =''''+Convert(Varchar,dateadd(QUARTER,-2,DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,GETDATE())+1,0))),101)+''''
set @Prior_Month_4 =''''+Convert(Varchar,dateadd(QUARTER,-1,DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,GETDATE())+1,0))),101)+''''


SET @Current_Month =null;

DECLARE  @month int;

SELECT
@Prior_month = CASE
 WHEN  MONTH(Getdate())  IN (1,2,3   )      THEN @Prior_Month_1
 WHEN  MONTH(Getdate())  IN (4,5,6   )    THEN @Prior_Month_2
 WHEN  MONTH(Getdate())  IN (7,8,9   )    THEN @Prior_Month_3
 WHEN  MONTH(Getdate())  IN (10,11,12)    THEN @Prior_Month_4

ELSE NULL END
 ,

  @Current_Month = ''''+ CONVERT(VARCHAR, DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,GETDATE()),0)),101)+''''