What's the equivalent for LISTAGG in postgres?

问题

I have to replace the Oracle driver with the newest postgres.

Postgres doesn't know the function LISTAGG. I have to concat values by comma separated.

What's the equivalent for the Oracle function LISTAGG in Postgres?

Thanks.

回答1:

The equivalent function in Postgres is string_agg()

select string_agg(col,',') from my_table

string_agg : input values concatenated into a string, separated by delimiter

回答2:

From Postgres 9.0 or later, I believe you could do something like this:

SELECT c_id, STRING_AGG(c_grp_id, ',' ORDER BY c_grp_id) AS group_ids 
FROM c_grp_at 
GROUP BY c_id

来源：https://stackoverflow.com/questions/29557563/whats-the-equivalent-for-listagg-in-postgres