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: 
The correct answer is in some of the comments (not in any of the answers, I don't think... 

incidentally, the shortcut keys for this are here:

![Picture of shortcut keys in Xcode for collapsing and expanding code](https://i.stack.imgur.com/KAsye.png)

Judging from past answers, this must have changed over time. This is from Xcode 6.1.1.
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 :/