Logical OR on Columns? (Merging two or more columns into one column)

[Marc Floessel]

Considering the following example table:

Column1 | Column2 | Column3
===========================
NULL |"Value1" | NULL
---------------------------
"Value2"| NULL | NULL
---------------------------
NULL | NULL |"Value3"

In each row only one column contains an actual value (a string in our
example), the other columns are set to NULL.

I would like to merge those columns into one single column, discarding
the NULL entries.

The desired result would look like this:

Merged_Column
=============
"Value1"
-------------
"Value2"
-------------
"Value3"

A '"SELECT column1 OR column2 OR column3 as "Merged_Column"' doesn't
work unfortunately. Is there an easy way to accomplish this on the SQL
Server?

The next problem I am going to face is that every column is in fact
made of a different data type (ie. Date, Int). Is there a way to
modify the merge select (if that's possible) to have it cast
everything into a single specific type? Ie. make everything in the
merged column a string.

Thanks,
Marc Floessel