Question

I want a query that will return a row for each column in a view, and a row for the view itself.

There should be a column basetable in the result that gives the base table for the column in the current row, and a column basefield in the result that gives the name of the column in the underlying query (for renamed columns). It would be a bonus if any calculations could also be included in the basefield column.

I don’t think this can be done. Am I wrong?

In the example below “what goes here” should be replaced by table1 or table2 as appropriate in the basetable column, and a, b, or c as appropriate in the basefield column.

create table table1 (a int, b int)
create table table2 (a int, c int)
go
create view view1 as select table1.a, table1.b, table2.c from table1 left join table2 on table1.a = table2.a
go

select * from 
(
 select 'View' objecttype,O.name viewname,'' fieldname,0 column_id,'' typename,'' max_length,'' [precision], '' scale, '' is_identity,
    'what goes here' basetable, '' basefield
 from sys.objects O where O.type='V' and O.[schema_id] = 1

 union all

  select 'Field' objecttype,object_name(C.[object_id]) viewname,C.name fieldname,C.column_id,T.name typename,C.max_length,C.precision,C.scale,C.is_identity,
  'what goes here' basetable, 'what goes here' basefield
  from sys.columns C
 left join sys.types T on C.user_type_id=T.system_type_id
 where C.[object_id] in (select O.[object_id] from sys.objects O where O.type='V')
) I
where viewname in ('view1')
order by viewname, column_id

drop view view1
drop table table1
drop table table2

Answer 1

There are few tables in the information schema that you can use to deduce the information. A basic query that gives you quite a bit of data will be:

select * 
from INFORMATION_SCHEMA.VIEW_COLUMN_USAGE v
    inner join INFORMATION_SCHEMA.COLUMNS v1
        on  v.VIEW_NAME=v1.TABLE_NAME and v.COLUMN_NAME=v1.COLUMN_NAME
where v.VIEW_NAME='My_View'

The tables in the information schema are:

select * from INFORMATION_SCHEMA.VIEWS
select * from INFORMATION_SCHEMA.VIEW_TABLE_USAGE
select * from INFORMATION_SCHEMA.VIEW_COLUMN_USAGE

So try using these.

However it works only when you use columns directly from the base tabbles without any formula ar deriving.