SELECT DISTINCT with LEFT JOIN, ORDERed BY in t-SQL

Question

I have the following table in SQL Server 2008:

CREATE TABLE tbl (ID INT, dtIn DATETIME2, dtOut DATETIME2, Type INT)

INSERT tbl VALUES
(1, \'05:00\', \'6:00\', 1         


        

Answer 1

You were having this error because you didnot put (tbl.dtOut) in the select list.

SELECT DISTINCT tbl.dtOut FROM tbl    
  LEFT JOIN tbl AS t1  
  ON tbl.type = t1.type AND  
     tbl.dtIn = t1.dtIn  
  ORDER BY tbl.dtOut ASC

Will get you a result set (having 3 rows) and if you want the id field too then

SELECT DISTINCT tbl.dtOut, tbl.ID FROM tbl      
  LEFT JOIN tbl AS t1  
  ON tbl.type = t1.type AND  
     tbl.dtIn = t1.dtIn  
  ORDER BY tbl.dtOut ASC  

(having 6 rows, as it gives the distinct combination off id/date field)