running balance

[Oliver Mercado]

Hi,

I am seeking help on how to display the following.

Total Amount = 260

+----+-------+--------+---------+
| id | debit | credit | balance |
+----+-------+--------+---------+
| 1 | NULL | 35 | NULL |
| 2 | 65 | NULL | 225 |
| 3 | NULL | 35 | NULL |
| 4 | 65 | NULL | 190 |
| 5 | 65 | NULL | 190 |
| 6 | 65 | NULL | 190 |
+----+-------+--------+---------+

I tried the query below but I don't get what I want

"SELECT id
, debit
, credit
, @balance := @balance+(COALESCE(debit,credit*-1)) balance
FROM my_table
, (SELECT @balance :=0) vars
ORDER
BY id;"

+----+-------+--------+---------+
| id | debit | credit | balance |
+----+-------+--------+---------+
| 1 | NULL | 35 | -35 |
| 2 | 65 | NULL | 30 |
| 3 | NULL | 35 | -5 |
| 4 | 65 | NULL | 60 |
| 5 | 65 | NULL | 125 |
| 6 | 65 | NULL | 190 |
+----+-------+--------+---------+