Question: I have a dataset with two columns as follows;

```
Prod Value
A    1
A    2
A    3
B    2
B    4
C    1
C    2

```

So I want all the rows where value is common for Prod, so in the example above only the following would be returned.

```
A   2
B   2
C   2 

```

Either LINQ or sql would be helpful

Thanks

Answer: 
Not sure if this is an OS change, or an Xcode change, but on **Lion with Xcode 4**, some of these commands cited by Griffo are performed with the Option modifier (the ⌥ key), not control. I've made some changes to reflect this:

```
Fold                       ⌥⌘←      option+command+left
Unfold                      ⌥⌘→      option+command+right
Unfold All                  ⌥U        option+U
Fold Methods/Functions      ⌥⌘↑      option+command+up
Unfold Methods/Functions    ⌥⌘↓      option+command+down

```

Sorry to necro a thread, but I thought this was worthwhile to revise.
I feel your pain. It is difficult to press cmd+option+shift+left every time I open an implementation file to collapse all the methods. I would be grateful to know of a way to set this by default. On the other hand, a probably obvious workaround may be to select the method from the method picker at the top of the window. I suppose this is how the Xcode developers intended us to find methods.. still cmd+option+shift+left is my preference.. it just hurts my hand :/