Suppose I have the following table:
ID Preferences
1 2
1 .
1 .
2 .
2 3
3 .
3 .
3 4
4 1
I have other columns before 'ID' and after 'Preferences'. What I want to get is two columns of the following type on the right of the above table:
ID Preferences
1 2
2 3
3 4
4 1
In other words, I want to delete the missing values of the variable 'Preferences'. I don't want to delete observations. I only want to record 'Preferences' with non-missing values. So
Code:
drop Preferences if Preferences != .
would not work in this case. This would delete observations with missing values for Preferences, which is not what I want.

How can I do this?