sql - Rails ordering with nil last

currently, trying order class limit attribute. want values in ascending order, nil values last.

i've tried couple different queries activerecord query along cross base sql query (it needs sql flexible). i've tried few:

self.order('isnull(limit), limit asc') self.order('case when -limit desc') self.order('limit null, limit desc')

but keep getting errors around limit, missing something?

sqlite3::sqlexception: near "isnull": syntax error: select "table".*       "table"  "table"."deleted_at" null order isnull(limit),    limit asc

limit null it, limit reserved keywork in sqlite3, enclose in backticks or quotes:

self.order('`limit` null')

hj