Re: [PHP] question, about mysql query

    This isn't a PHP question at all.  It's a MySQL question.
However, answers are below, with forwards to the appropriate lists for
archiving purposes.

On Mon, Jun 2, 2008 at 9:19 PM, LKSunny <[email protected]> wrote:
> two table, tablea and tableb
> tablea
> uid, col1, col2, col3
> 1,    xx, xx, xx
> 2,    xx, xx, xx
> 3,    xx, xx, xx
> tableb
> id, uid, col1, firstdata
> 1, 1, xx, 1
> 2, 2, xx, 0
> 3, 2, xx, 0
> 4, 1, xx, 0
>
> i want query tablea, and join tableb, uid is associate, ok "LEFT JOIN
> `tableb` b ON a.uid = b.uid", and than i want tableb firstdata=1 or tableb
> no associate uid "b.firstdata=1 OR b.uid IS NULL", by the time all ok, but i
> want add one case, if tableb firstdata all is 0, result one row, like b.uid
> IS NULL, i don't know how to
>
> i want result is all tablea data no double, tableb one case firstdata is 1
> (one uid in tableb just one row possible is firstdata=1), or no row in
> tableb, or all firstdata = 0
>
> Thank You Very Much !!
>
> This query can't
> SELECT a.*, b.* FROM `tablea` a LEFT JOIN `tableb` b ON a.uid = b.uid WHERE
> (b.firstdata=1 OR b.firstdata=0 OR b.uid IS NULL)

    Okay, I had a difficult time understanding what it is you need,
but hopefully got enough from your message to be able to help you out.
 What I think you may be looking for is something like this:

SELECT * FROM tableb WHERE firstdata='1' AND id IN (SELECT DISTINCT id
FROM tablea ORDER BY id ASC);

    That will select only unique `id` columns from `tablea` and select
only the rows from `tableb` where the `id` columns match and
`firstdata` is set to '1'.  You can then modify that query as needed.

-- 
</Daniel P. Brown>
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