Обсуждение: nested inner join help
I have a query which works perfectly fine in mysql but won't
work in the same database in postgres...
Can anyone take a look at this and tell me what the problem is?
I get a parser error at (.
SELECT orderlines.quantity, products.productname, products.productcost, customers.custlname,customers.custfname
FROM (((orders INNER JOIN orderlines ON orders.orderid = orderlines.lnkorderid) INNER JOIN customers ON (customers.custid = orders.lnkcustid)) INNER JOIN products ON (products.productid = orderlines.lnkproductid))
WHERE (((orders.orderid)=2));
FROM (((orders INNER JOIN orderlines ON orders.orderid = orderlines.lnkorderid) INNER JOIN customers ON (customers.custid = orders.lnkcustid)) INNER JOIN products ON (products.productid = orderlines.lnkproductid))
WHERE (((orders.orderid)=2));
It seems as soon as I try to nest an INNER JOIN I get these parser errors. I have tried this query a few different ways, and still cant get it to work.
Thank you so much!!
Darryl Wolski
Darryl, In Postgres, neither the parentheses nor the word "INNER" are required. Youwill significantly simplify your life if youget rid of them, and clean upyour presentation of SQL text in order to debug your own joins. One significant MSAccess <==> Postgres conflict is that Postgres assumes thatparens in the FROM clause represent subselects(I think), while MS Access usesparens to organize JOINs. Postgres behavior is, of course, more SQL92correct. SELECT orderlines.quantity, products.productname, products.productcost,customers.custlname,customers.custfname FROM orders JOIN orderlines ON orders.orderid = orderlines.lnkorderid JOIN customers ON customers.custid = orders.lnkcustid JOIN products ON products.productid = orderlines.lnkproductid WHERE orders.orderid=2; -Josh Berkus ______AGLIO DATABASE SOLUTIONS___________________________ Josh Berkus Complete informationtechnology josh@agliodbs.com and data management solutions (415) 565-7293 for law firms, small businesses fax 621-2533 and non-profit organizations. San Francisco
"Darryl M. Wolski" <drwolski@sympatico.ca> writes:
> Can anyone take a look at this and tell me what the problem is?
> I get a parser error at (.
> SELECT orderlines.quantity, products.productname, products.productcost, cus=
> tomers.custlname,customers.custfname
> FROM (((orders INNER JOIN orderlines ON orders.orderid =3D orderlines.lnkor=
> derid) INNER JOIN customers ON (customers.custid =3D orders.lnkcustid)) IN=
> NER JOIN products ON (products.productid =3D orderlines.lnkproductid))
> WHERE (((orders.orderid)=3D2));
Looks fine to me. Are you using an old Postgres version? We didn't
support JOIN keywords until 7.1.
regards, tom lane
"Josh Berkus" <josh@agliodbs.com> writes:
> One significant MSAccess <==> Postgres conflict is that Postgres assumes that
> parens in the FROM clause represent subselects (I think),
Huh? Parenthesizing JOINs is perfectly valid, and I think it's good
style too in complex cases. See the nearby "SQL Joins" thread for
an example of a query that's quite unreadable without 'em.
regards, tom lane
Tom, > Huh? Parenthesizing JOINs is perfectly valid, and I think it's good > style too in complex cases. See the nearby "SQL Joins" thread for > an example of a query that's quite unreadable without 'em. Aha. I see. Of course, the OUTER JOINs here sort of require parens. So, Darryl, you do want to use parens some of time. Just to make it harder foryou to decide. However, I would assert thatin your example query they arenot necessary and actually make the syntax more difficult. -Josh Berkus ______AGLIO DATABASE SOLUTIONS___________________________ Josh Berkus Complete informationtechnology josh@agliodbs.com and data management solutions (415) 565-7293 for law firms, small businesses fax 621-2533 and non-profit organizations. San Francisco