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Thread: Select clause in JOIN statement

Select clause in JOIN statement

From
JORGE MALDONADO
Date:
<div dir="ltr">Is it valid to specify a SELECT statement as part of a JOIN clause?<div style="style"><br /></div><div
style="style">Forexample:</div><div style="style"><br /></div><div style="style">SELECT table1.f1, table1.f2 FROM
table1</div><divstyle="style">INNER JOIN </div><div style="style">(SELECT table2.f1, table2.f2 FROM table2) table_aux
ONtable1.f1 = table_aux.f1</div><div style="style"><br /></div><div style="style">Respectfully,<br /></div><div
style="style">JorgeMaldonado</div></div>

Re: Select clause in JOIN statement

From
Luca Vernini
Date:
It works.
Also consider views.

Just used this on a my db:

SELECT * FROM tblcus_customer
INNER JOIN
( SELECT * FROM tblcus_customer_status WHERE status_id > 0) AS b
ON tblcus_customer.status = b.status_id


You can even join with a function result.

Regards,

Luca.

2013/6/14 JORGE MALDONADO <jorgemal1960@gmail.com>:
> Is it valid to specify a SELECT statement as part of a JOIN clause?
>
> For example:
>
> SELECT table1.f1, table1.f2 FROM table1
> INNER JOIN
> (SELECT table2.f1, table2.f2 FROM table2) table_aux ON table1.f1 =
> table_aux.f1
>
> Respectfully,
> Jorge Maldonado

Re: Select clause in JOIN statement

From
Andreas Joseph Krogh
Date:
<div>På fredag 14. juni 2013 kl. 01:10:51, skrev Luca Vernini <<a href="mailto:lucazeo@gmail.com"
target="_blank">lucazeo@gmail.com</a>>:</div><blockquotestyle="border-left: 1px solid rgb(204, 204, 204); margin:
0pt0pt 0pt 0.8ex; padding-left: 1ex;"><div style="display:inline; font-family: monospace; font-size: 12px;">It
works.<br/> Also consider views.<br /><br /> Just used this on a my db:<br /><br /> SELECT * FROM tblcus_customer<br />
INNERJOIN<br /> ( SELECT * FROM tblcus_customer_status WHERE status_id > 0) AS b<br /> ON tblcus_customer.status =
b.status_id</div></blockquote><div> </div><div>Thisquery is the same as a normal JOIN:</div><div><style
type="text/css"></style><preclass="western" style="background: #ffffff; border: none; padding: 0in"> 
<font color="#000080"><font face="DejaVu Sans Mono"><b>SELECT</b> </font></font><font color="#000000"><font
face="DejaVuSans Mono">*</font></font> 
<font face="DejaVu Sans Mono"><font color="#000080"><b>FROM </b></font><font
color="#000000">tblcus_customer</font></font>
<font color="#000000">    </font><font color="#000080"><font face="DejaVu Sans Mono"><b>INNER JOIN</b></font></font>
<font color="#000080">    </font><font color="#000000"><font face="DejaVu Sans Mono">tblcus_customer_status
b</font></font>
<font color="#000000">        </font><font color="#000080"><font face="DejaVu Sans Mono"><b>ON </b></font></font><font
color="#000000"><fontface="DejaVu Sans Mono">tblcus_customer.status = b.status_id </font></font><font
color="#000080"><fontface="DejaVu Sans Mono"><b>AND </b></font></font><font color="#000000"><font face="DejaVu Sans
Mono">b.status_id> </font></font><font color="#0000ff"><font face="DejaVu Sans Mono">0</font></font> 
</pre> or</div><div><style type="text/css"></style><pre class="western" style="background: #ffffff; border: none;
padding:0in"> 
<font color="#000080"><font face="DejaVu Sans Mono"><b>SELECT</b></font> </font><font color="#000000"><font
face="DejaVuSans Mono">*</font></font> 
<font face="DejaVu Sans Mono"><font color="#000080"><b>FROM </b></font><font
color="#000000">tblcus_customer</font></font>
<font color="#000000">    </font><font color="#000080"><font face="DejaVu Sans Mono"><b>INNER JOIN</b></font></font>
<font color="#000080">    </font><font color="#000000"><font face="DejaVu Sans Mono">tblcus_customer_status
b</font></font>
<font color="#000000">        </font><font color="#000080"><font face="DejaVu Sans Mono"><b>ON </b></font></font><font
color="#000000"><fontface="DejaVu Sans Mono">tblcus_customer.status = b.status_id</font></font> 
<font face="DejaVu Sans Mono"><font color="#000080"><b>WHERE </b></font><font color="#000000">b.status_id >
</font><fontcolor="#0000ff">0</font></font></pre> But you can JOIN on SELECTs selecting arbitrary
stuff.</div><div> </div><divclass="origo-email-signature">--<br /> Andreas Joseph Krogh <andreak@officenet.no>   
 mob: +47 909 56 963<br /> Senior Software Developer / CTO - OfficeNet AS - http://www.officenet.no<br /> Public key:
http://home.officenet.no/~andreak/public_key.asc</div><div> </div>