Re: Subquery error. Help please!!
От | Wei Weng |
---|---|
Тема | Re: Subquery error. Help please!! |
Дата | |
Msg-id | 993739583.577.0.camel@Monet обсуждение исходный текст |
Ответ на | Subquery error. Help please!! ("kakerjak" <kakarotto@canada.com>) |
Список | pgsql-sql |
What version of postgresql are you using? On 27 Jun 2001 17:09:14 -0400, kakerjak wrote: > Hey all.. > > Here's the table definition. > CREATE TABLE "laboratory" ( > "id" "int4" NOT NULL, > "subid" "int2" NOT NULL, > "name" varchar(30) NOT NULL, > CONSTRAINT "laboratory_pkey" PRIMARY KEY ("id", "subid")) > > The way this table works is that each lab has one ID. If any information is > changed(there are actually more fields then what i showed, but they don't > affect the problem) then the ID remains the same, but the SUBID gets > incremented by 1. Thus, other tables linking to it just need to know the ID > and then read the ID with the biggest SUBID to get the most recent record. > > Now, what I want to do is this. Create a list of all the laboratories using > only the most recent record for each (the biggest SUBID for every unique > ID). > > Here's my select statement. > > SELECT b.id, b.subid, b.name > FROM (SELECT c.id, MAX(c.subid) AS subid FROM laboratory AS c GROUP BY > id) AS a > INNER JOIN > laboratory AS b > USING id, subid > > The subquery works on it's own and returns the desired ID, SUBID > combinations. > But when put into the other query I get parser errors. > If the subquery is placed before the JOIN, like it is above, then the error > i get says 'parse error at or near "select"' > If i flip the subquery around with the laboratory table then i get 'parse > error at or near "("' > > According to the documention online, it seems as if this statement should > work. > ( http://www.postgresql.org/idocs/index.php?queries.html#QUERIES-FROM ) > > Any help would be appreciated. TIA > kakerjak > > > > ---------------------------(end of broadcast)--------------------------- > TIP 4: Don't 'kill -9' the postmaster > -- Wei Weng Network Software Engineer KenCast Inc.
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