How to calculate running total in SQL
<p>I have my dataset in the given format
It's a month level data along with salary for each month.
I need to calculate cumulative salary for each month end. How can I do this</p>

<pre><code>+----------+-------+--------+---------------+
| Account  | Month | Salary | Running Total |
+----------+-------+--------+---------------+
| a        |     1 |    586 |           586 |
| a        |     2 |    928 |          1514 |
| a        |     3 |    726 |          2240 |
| a        |     4 |    538 |           538 |
| b        |     1 |    956 |          1494 |
| b        |     3 |    667 |          2161 |
| b        |     4 |    841 |          3002 |
| c        |     1 |    826 |           826 |
| c        |     2 |    558 |          1384 |
| c        |     3 |    558 |          1972 |
| c        |     4 |    735 |          2707 |
| c        |     5 |    691 |          3398 |
| d        |     1 |    670 |           670 |
| d        |     4 |    838 |          1508 |
| d        |     5 |   1000 |          2508 |
+----------+-------+--------+---------------+
</code></pre>

<p>I need to calculate running total column which is cumulative column. How can I do efficiently in SQL?</p>