How to convert following sql query to linq
SELECT top 1 Id, Name, Address,refNbr FROM tbl1 WHERE Name is not Null and refNbr='abc123' Union select l.Id,a.FirstName a.ResidenceAddress1, l.refNbr from tbl2 l, tbl3 a, tbl4 b where b.auto = 1 and l.Id = b.Id and l.Id = a.Id and l.refNbr = 'abc123'
Please do let me know how to convert this sql query written using union into linq in c sharp