National level survey data

[Sunshine bae]

Hello,
I have a national level survey dataset. On household level, it has around 5988 observation. But I only need observations of rural household. How should I code that

[Fei Wang]

There must be a variable indicating whether a household is from urban or rural. For example, a variable called "region" being 1 for urban households and 2 for rural households. Then the code below only keeps rural households.

keep if region == 2

[Sunshine bae]

I did that for one dataset. But when I merged it with another dataset, due to mismatch in observation, STATA recoded those dropped observations as . Or missing.
ps. There is so such region variable for all datasets.

[Sunshine bae]

I used the merge command for the matched variables and it worked.