I haven't had much experience with SQL and it strikes me as a simple question, but after an hour of searching I still can't find an answer...

I have a table that I want to add up the totals for based on ID - e.g:

```
-------------
ID   Quantity  
1        30  
2        11  
1         4  
1         3  
2        17  
3        16  
.............

```

After summing the table should look something like this:

```
-------------
ID   Quantity
1        37
2        28
3        16

```

I'm sure that I need to use the DISTINCT keyword and the SUM(..) function, but I can only get one total value for all unique value combinations in the table, and not separate ones like above. Help please :)