How To Assign New Column Names in a View?

By default, column names in a view are provided by the underlying SELECT statement.

But sometimes, the underlying SELECT statement can not provide names for output columns that specified as expressions with functions and operations. In this case, you need to assign new names for the view's columns. The tutorial exercise below creates a view to merge several table columns into a single view column with a format called CSV (Comma Separated Values):

CREATE VIEW fyi_links_dump AS
   SELECT CONVERT(VARCHAR(20),id) 
      + ', ' + CONVERT(VARCHAR(20),counts) 
      + ', ''' + url + ''''
   FROM fyi_links WHERE counts > 1000
GO
Msg 4511, Level 16, State 1, Procedure fyi_links_dump, 
   Line 2
Create View or Function failed because no column name 
   was specified for column 1.

CREATE VIEW fyi_links_dump (Line) AS
   SELECT CONVERT(VARCHAR(20),id) 
      + ', ' + CONVERT(VARCHAR(20),counts) 
      + ', ''' + url + ''''
   FROM fyi_links WHERE counts > 1000
GO

SELECT TOP 3 * FROM fyi_links_dump
GO
Line
------------------------------------------------------------
7600, 237946, '  eyfndw jdt  lee ztejeyx l q  jdh k '
19437, 222337, '  eypx u x'
55924, 1877, '  eyq ntohxe i rtnlu riwaskzp  cucoa dva c rc'

The first CREATE VIEW gives you an error, because the SELECT statement returns no column for the concatenated value, and no view column name is specified explicitly.