Can SQL Server Retrieve Column Data Using Ordinal Position?

Is Ordinal Position-Based Column Selection Possible in SQL Server?

Selecting column data based on ordinal positions is generally discouraged, but certain scenarios may warrant its use. This question explores the possibility of such selection in SQL Server.

Question:

Can we retrieve column data using the ordinal position of a table column? As an example, consider the following table:

create table Test(
    Col1 int,
    Col2 nvarchar(10)
)

Instead of selecting using the column name:

select Col2 from Test

Can we write:

select "2" from Test -- for illustration purposes only

Answer:

While SQL Server does not natively support selecting columns by ordinal position, a workaround can be achieved by exploiting the Cartesian product operation:

select NULL as C1, NULL as C2 where 1 = 0
-- Returns empty table with predefined column names
union all
select * from Test
-- There should be exactly 2 columns, but names and data type doesn't matter

This results in a table with two columns ([C1] and [C2]) that match the number of columns in the Test table. By selecting the second column of this Cartesian product, we effectively retrieve the data from the second column of the Test table.

Note that this method is only practical for tables with a predefined number of columns. Using it for tables with a large number of columns can be inefficient and error-prone.

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