Postgresql how to update existing array values?

Question

PostgreSQL

There is a Postgresql chat_channels table with a users integer[] NOT NULL DEFAULT ARRAY[]::integer[] column
. It stores user id arrays.
How to replace the id of a certain user with the id of another in all rows of the table where this id is? The rest of the array elements should remain unchanged.
Thank you.

Answer 1

update tablename set users = array_replace(users, :from, :to) where users @> array[:from]

It may be necessary to add explicit type casting, depending on how the parameters will be substituted.