Hi This recurring question has a simple solution in MonetDB for most of the cases considered. Simple rip out the subquery and encapsulate it in table producing function. The following example shows how: -- select * from tables where id in (select id from tables limit 1); create function limited() returns table (id integer) begin return select id from tables order by id desc limit 1; end; select * from tables where id in (select * from limited()); regards, Martin On 05/11/14 16:52, Martin Kersten wrote:
Hi
A possible workaround is to enclose the query in a table producing function.
regards, Martin
On 05/11/14 16:49, Leo Kotschenreuther wrote:
Hi,
I understand why Monetdb does’t support ORDER BY in subqueries.
An ORDER BY combined with a LIMIT does influence the size of the query result set. Is there a workaround to use such a query?
Here’s my use case: I’m working with the spatial extension and have a table filled with polygons. Now I want to know the ids of all polygons that intersect the polygon with the biggest area.
Is there a chance to answer this use case with only one query?
Regards Leo
On 27 Oct 2014, at 19:02, Martin Kersten
wrote: Hi
ORDER BY (and LIMIT/OFFSET for that matter) only control the overall shape of the query result set. Hence, they are indeed not supported within subqueries in MonetDB.
See thread https://www.monetdb.org/pipermail/users-list/2013-October/006861.html
regards, Martin
On 27/10/14 17:57, Kotschenreuther, Leo wrote:
Hi all,
I tried to use some more complex queries, they contained subqueries. I will shortly desrcibe the situation:
I have two tables (e.g. test and foo) and want to join them. Furthermore I want to preselect a subset of one of the two tables by adding some conditions (e.g. order the records by attribute c and only choosing the biggest one). A query could look like the this:
*sql>select * from test join (select * from foo order by c limit 1);* * * The result I receive is the following:
*syntax error, unexpected ORDER, expecting INTERSECT or EXCEPT or UNION or ')' in: "select * from test join (select * from foo order**”* * * On the other hand, I can run the subquery without the main query and I receive a valid result.
Is there a possibility to use subqueries with an ORDER BY statement without separating them into two independent queries?
Regards Leo
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