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: 
If you want to fold / unfold specific blocks of code, since Xcode 7, you have to enable that.

Go to Xcode > Preferences > Text Editing > and check 'Code folding ribbon'.

[![Xcode's Text Editing preferences](https://i.stack.imgur.com/lJw6d.png)](https://i.stack.imgur.com/lJw6d.png)

(No idea why they disabled this useful feature by default.)
For the sake of completeness, 

```
Fold All        ⌘⌥⇧←    command+option+shift+left

```