merging datasets

[luizaandrade]

webuse dollars, clear
list
webuse sforce
list

merge m:1 region using https://www.stata-press.com/data/r18/dollars, assert(3)

Check that the number of matched and unmatched observations is stable

count if _merge == 3
assert r(N) == 1

count if _merge == 1
assert r(N) == 3

Using advanced options

merge 1:1 id using data
drop if _merge == 1
drop    _merge

merge 1:1 id using data, keep(2 3) nogen

[luizaandrade]

Creating pairwaise combinations (many-to-many merge)

joinby [varlist] using filename [, options]