SQL: Select like column from two tables

Question

I have a database with two tables (Table1 and Table2). They both have a common column [ColumnA] which is an nvarchar.

How can I select this column from both tables and return it as a single column in my result set?

So I'm looking for something like:

ColumnA in Table1:
a
b
c

ColumnA in Table2:
d
e
f

Result set should be:
a
b
c
d
e
f

Answer 1

SELECT ColumnA FROM Table1 UNION Select ColumnB FROM Table2 ORDER BY 1

Also, if you know the contents of Table1 and Table2 will NEVER overlap, you can use UNION ALL in place of UNION instead. Saves a little bit of resources that way.

-- Kevin Fairchild

Answer 2

Do you care if you get dups or not?

UNION will be slower than UNION ALL because UNION will filter out dups

Answer 3

Use the UNION operator:

SELECT ColumnA FROM Table1
UNION
SELECT ColumnA FROM Table2

Answer 4

The union answer is almost correct, depending on overlapping values:

SELECT distinct ColumnA FROM Table1
UNION
SELECT distinct ColumnA FROM Table2

If 'd' appeared in Table1 or 'c' appeared in Table2 you would have multiple rows with them.