ruby – 使用续集gem的多个聚合查询

dataset = DB.select {[ 
  DB[:users].where(blah: 'blah').select { count('*') }.as(:users),DB[:contacts].where(blah: 'blah').select { count('*') }.as(:contacts) 
]}

dataset.first
# => { users: X,contacts: Y }

dataset.sql
# => "SELECT (SELECT count('*') FROM "users" WHERE ("blah" = 'blah')) AS "users",#            (SELECT count('*') FROM "contacts" WHERE ("blah" = 'blah')) AS "contacts""