Conditional UNION!

Hi all,
I have a query that if it returns data i want to perform a union on it.
IE: Select * FROM myTable WHERE myColumn = 'a' ORDER BY NEWID()
If (? Above query returns rows)
UNION
SELECT * FROM myTable 2 WHERE myColumn = 'b' ORDER BY NEWID
Is this kind of thing possible'
A basic example would be great!!
Cheers,
Adam."Adam Knight" <adam@.pertrain.com.au> wrote in message
news:OKNz$V9wFHA.3644@.TK2MSFTNGP11.phx.gbl...
> Hi all,
> I have a query that if it returns data i want to perform a union on it.
> IE: Select * FROM myTable WHERE myColumn = 'a' ORDER BY NEWID()
> If (? Above query returns rows)
> UNION
> SELECT * FROM myTable 2 WHERE myColumn = 'b' ORDER BY NEWID
> Is this kind of thing possible'
>
Would this work?
Select *
FROM myTable
WHERE myColumn = 'a'
UNION
SELECT *
FROM myTable
WHERE myColumn = 'b'
and exists(
Select *
FROM myTable
WHERE myColumn = 'a')
Regards,
John|||Adam
Is there any reason to use UNION instead of UNION ALL? Do you want to
eliminate duplications?
"Adam Knight" <adam@.pertrain.com.au> wrote in message
news:OKNz$V9wFHA.3644@.TK2MSFTNGP11.phx.gbl...
> Hi all,
> I have a query that if it returns data i want to perform a union on it.
> IE: Select * FROM myTable WHERE myColumn = 'a' ORDER BY NEWID()
> If (? Above query returns rows)
> UNION
> SELECT * FROM myTable 2 WHERE myColumn = 'b' ORDER BY NEWID
> Is this kind of thing possible'
> A basic example would be great!!
> Cheers,
> Adam.
>
>|||Yes!
"Uri Dimant" <urid@.iscar.co.il> wrote in message
news:edBylb%23wFHA.3000@.TK2MSFTNGP12.phx.gbl...
> Adam
> Is there any reason to use UNION instead of UNION ALL? Do you want to
> eliminate duplications?
>
> "Adam Knight" <adam@.pertrain.com.au> wrote in message
> news:OKNz$V9wFHA.3644@.TK2MSFTNGP11.phx.gbl...
>|||Try:
SELECT DISTINCT *
FROM MyTable
WHERE mycolumn IN ('A','B')
AND EXISTS
(SELECT *
FROM MyTable
WHERE mycolumn = 'A') ;
ORDER BY NEWID() fails under UNION or DISTINCT unless you also add NEWID()
to the SELECT list (in which case duplicates would not be eliminated).
Apparently your table doesn't have a key. I suggest you fix that problem
first but I don't see how this query helps you do that.
If the above doesn't help, please post DDL, sample data and required results
as suggested here:
http://www.aspfaq.com/etiquette.asp?id=5006
David Portas
SQL Server MVP
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