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

Use the UNION operator:

SELECT ColumnA FROM Table1
UNION
SELECT ColumnA FROM Table2

Answer 3

You can use a union select:

Select columnA from table1 union select columnA from table2

Answer 4

SELECT Table1.*, Table2.d, Table2.e, Table2.f 
FROM Table1 JOIN Table2 ON Table1.a = Table2.a

Or am I misunderstanding your question?

Edit: It appears I did.

Answer 5

I believe it's:

SELECT columna FROM table1 UNION SELECT columnb FROM table2;

Answer 6

Do you care if you get dups or not?

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

Answer 7

In Oracle (at least) there is UNION and UNION ALL, UNION ALL will return all results from both sets even if there are duplicates, where as UNION will return the distinct results from both sets.

Answer 8

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.