I have a set of data where an account id can have multiple rows of country. I'm looking for an array function that will give me a unique list of accounts with the countries in the second column as csv values e.g. country1,country1,country3.
If I unique the accounts, this query will do it per row but I'm really looking for an array so I don't have to maintain it as the number of rows grows.
=TEXTJOIN(",",1,UNIQUE(QUERY(A:B,"select B where A = '"&D2&"'",0)))
try:
=INDEX(REGEXREPLACE(TRIM(SPLIT(FLATTEN(QUERY(QUERY(
IF(A2:A="",,{A2:A&"×", B2:B&","}),
"select max(Col2)
where not Col2 matches '^×|^$'
group by Col2
pivot Col1"),,9^9)), "×")), ",$", ))