Backfilling empty observations based on same id

[Maroun Mezher]

Hello everyone,

I have recently encountered a couple of data set in which the first contains main player attributes and the second contains secondary attributes. The first one also contains signing info for the player that I would like to expand to all the observations for a player post merge. Is there a way to backfill the missing observations based on the first one? Here is what my data looks like (sorted by name, _merge):

player_name	signing_year	signing_source	attributes	_merge
Alfredo	2021	High School	Center Attack	(1) master
Alfredo	.		Right Winger	(2) using
Alfredo	.		Right Inverted Forward	(2) using
Michael	2019	College	Center Back	(1) master
Michael	.		Deep Center Back	(2) using
Xavier	2023	College	Midfield Left	(1) master
Xavier	.		Advanced Playmaker	(2) using
Xavier	.		Deep Lying Playmaker	(2) using

Thank you!

[Clyde Schechter]

sort player_name _merge
foreach v of varlist signing_year signing_source {
    by player_name (_merge): replace `v' = `v'[1] if missing(`v')
}

[Maroun Mezher]

This works, thank you