How to get the the sum using variable SQL

Question

Here's my query...

+-----+----+----+------------+------------+-----+----------+-------+----------+
| seq | i  | WN | fld_Date   | next_date  | CBU | balance  | ndays | tbal     |
+-----+----+----+------------+------------+-----+----------+-------+----------+
|  67 |  1 | 46 | 2012-11-13 | 2012-11-20 | 50  | 50.00    |     7 | 350.00   |
|  68 |  2 | 47 | 2012-11-20 | 2012-11-27 | 50  | 100.00   |     7 | 700.00   |
|  69 |  3 | 48 | 2012-11-27 | 2012-12-04 | 50  | 150.00   |     7 | 1,050.00 |
|  70 |  4 | 49 | 2012-12-04 | 2012-12-11 | 50  | 200.00   |     7 | 1,400.00 |
|  71 |  5 | 50 | 2012-12-11 | 2012-12-18 | 50  | 250.00   |     7 | 1,750.00 |
|  72 |  6 | 51 | 2012-12-18 | 2012-12-25 | 50  | 300.00   |     7 | 2,100.00 |
|  73 |  7 | 52 | 2012-12-25 | 2013-01-01 | 50  | 350.00   |     7 | 2,450.00 |
|  74 |  8 |  1 | 2013-01-01 | 2013-01-08 | 50  | 400.00   |     7 | 2,800.00 |
|  75 |  9 |  2 | 2013-01-08 | 2013-01-15 | 50  | 450.00   |     7 | 3,150.00 |
|  76 | 10 |  3 | 2013-01-15 | 2013-01-22 | 50  | 500.00   |     7 | 3,500.00 |
|  77 | 11 |  4 | 2013-01-22 | 2013-01-29 | 50  | 550.00   |     7 | 3,850.00 |
|  78 | 12 |  5 | 2013-01-29 | 2013-02-05 | 50  | 600.00   |     7 | 4,200.00 |
|  79 | 13 |  6 | 2013-02-05 | 2013-02-12 | 50  | 650.00   |     7 | 4,550.00 |
|  80 | 14 |  7 | 2013-02-12 | 2013-02-19 | 50  | 700.00   |     7 | 4,900.00 |
|  81 | 15 |  8 | 2013-02-19 | 2013-02-26 | 50  | 750.00   |     7 | 5,250.00 |
|  82 | 16 |  9 | 2013-02-26 | 2013-03-05 | 50  | 800.00   |     7 | 5,600.00 |
|  83 | 17 | 10 | 2013-03-05 | 2013-03-12 | 50  | 850.00   |     7 | 5,950.00 |
|  84 | 18 | 11 | 2013-03-12 | 2013-03-19 | 50  | 900.00   |     7 | 6,300.00 |
|  85 | 19 | 12 | 2013-03-19 | 2013-03-26 | 50  | 950.00   |     7 | 6,650.00 |
|  86 | 20 | 13 | 2013-03-26 | 2013-04-02 | 50  | 1,000.00 |     7 | 7,000.00 |
|  87 | 21 | 14 | 2013-04-02 | 2013-04-09 | 50  | 1,050.00 |     7 | 7,350.00 |
|  88 | 22 | 15 | 2013-04-09 | 0          | 50  | 1,100.00 |     0 | 0.00     |
+-----+----+----+------------+------------+-----+----------+-------+----------+

All I want is to sum up the tbal, ndays and balance but i got a problem in tbal when i use SUM function.. This must be the output that i try to get.... pls. help me with this thanks...

cbu = 1,100.00
balance = 12,650.00
ndays = 147 
tbal = 80,850.00

here's the sql...

SELECTseq,@i := @i + 1 i,WEEKOFYEAR(fld_Date) AS WN,fld_Date,next_date,CBU,FORMAT(COALESCE (@balance := @balance + CBU, 0),2) AS balance,(@ndays := COALESCE (DATEDIFF(next_date, fld_Date),0)) ndays,FORMAT(@tbal := COALESCE (@Balance *@ndays, 0),2) AS tbal FROM (SELECT db_lms.lms_savings.seq,@d next_date,@d := db_lms.lms_savings.fld_Date fld_Date,  db_lms.lms_savings.CBU FROM db_lms.lms_savings,(SELECT @d := 0) d,(SELECT @balance := 0) e ORDER BY db_lms.lms_savings.seq DESC) q,(SELECT @i := 0) n ORDER BY seq;

Answer 1

UPDATED

SELECT SUM(cbu) cbu, 
       FORMAT(SUM(balance), 2) balance, -- you have to move FORMAT to outer SELECT
       SUM(ndays) ndays, 
       FORMAT(SUM(tbal), 2) tbal  -- you have to move FORMAT to outer SELECT
FROM
(
SELECT seq, 
       @i := @i + 1 i,
       WEEKOFYEAR(fld_Date) WN,
       fld_Date,
       next_date,
       CBU,
       COALESCE (@balance := @balance + CBU, 0) balance,
       (@ndays := COALESCE (DATEDIFF(next_date, fld_Date),0)) ndays,
       @tbal := COALESCE (@Balance * @ndays, 0) tbal 

 -- rest of your current query goes here !!! without semicolon at the end !!!
) z

Output:

|  CBU |   BALANCE | NDAYS |      TBAL |
----------------------------------------
| 1100 | 12,650.00 |   147 | 80,850.00 |

Here is SQLFiddle demo