Now to enable it from back end SQL you need to update enable flag to 1 and provide SID in UserInfo table to get SID you can user following job as provided in Screenshot in some other application in but in same domain
then use following query in SQL
select * from USERINFO where ID = 'secu'
update USERINFO set ENABLE = 1 where ID = 'secu'
update USERINFO set SID = 'S-1-5-21-2656439898-1577874530-2966910584-8962' where ID = 'secu'
all this to enable from SQL ...........
Cheerz.......