Left outer join - how to return a boolean for existence in the second table?
"IS NULL" and "IS NOT NULL" return a boolean, so this should make it easy.
I think this is all you need?
SELECT b.id IS NOT NULL as is_banned, -- The value of "is_banned" will be a booleanNot sure if you need the "NOT" or not, but you'll get a bool either way.
A CASE or COALESCE statement with an outer join IS the proper way to do this.
select CASE WHEN b.id IS NULL THEN true ELSE false END AS banned, u.id, u.first_name, u.last_name, u.city, u.last_ip, to_char(u.login, 'DD.MM.YYYY') as dayfrom pref_users u left outer join pref_ban2 b on u.id=b.idlimit 10;