I have this table:

```
Dimension letter value Calculation
--------------------------------------------
Length1 H 20 NULL
Length2 U 10 NULL
Total T H + U
```

I need to calculate the total Length according to the formula described in column "Calculation". The table is then exported to a web application, The calculation con be either made in SQL (no idea how this could be achieved) or in c#, which gets rather complicated, but I guess I could find a solution.

Anybody an idea of how to do this with SQL?.