cayenne-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From John Huss <johnth...@gmail.com>
Subject Re: Aggregate function
Date Fri, 15 Jul 2016 18:08:54 GMT
That's the query you don't want. You want a DataRow object not a Reading.
On Fri, Jul 15, 2016 at 12:58 PM Harunobu Oyama <ho@telensa.com> wrote:

> John,
>
> So, there is no Cayenne native way to perform a query such as SELECT
> MAX("reading_id") FROM "reading"  ?
> It sounds like you are recommending to write another query to fetch a
> record with max reading_id instead.
>
> Indeed, the code below worked.
>
>   SQLTemplate query = new SQLTemplate( Reading.class, "SELECT * FROM
> \"reading\" WHERE \"reading_id\"=( SELECT MAX(\"reading_id\") FROM
> \"reading\" )" );
>   List result = context.performQuery( query );
>
> thank you,
> nobu
>
>
>
>
> On 15 July 2016 at 18:35, John Huss <johnthuss@gmail.com> wrote:
>
> > Make sure your sqltemplate us set to fetch datarows (hashmap) not objects
> > On Fri, Jul 15, 2016 at 12:27 PM Harunobu Oyama <ho@telensa.com> wrote:
> >
> > > Michael,
> > >
> > > The min connection and max connection are both 1 as default.
> > >
> > > nobu
> > >
> > >
> > > On 15 July 2016 at 18:16, Michael Gentry <blacknext@gmail.com> wrote:
> > >
> > > > On Fri, Jul 15, 2016 at 12:39 PM, Harunobu Oyama <ho@telensa.com>
> > wrote:
> > > >
> > > > > Caused by: java.sql.SQLException: Can't obtain connection. Request
> > > timed
> > > > > out. Total used connections: 1
> > > > > at
> > > > >
> > > > >
> > > >
> > >
> >
> org.apache.cayenne.conn.PoolManager.uncheckPooledConnection(PoolManager.java:454)
> > > > > at
> > > >
> org.apache.cayenne.conn.PoolManager.getConnection(PoolManager.java:382)
> > > > > at
> > > >
> org.apache.cayenne.conn.PoolManager.getConnection(PoolManager.java:371)
> > > > > at
> > > > >
> > > > >
> > > >
> > >
> >
> org.apache.cayenne.configuration.server.DefaultDbAdapterFactory.detectAdapter(DefaultDbAdapterFactory.java:97)
> > > > > ... 15 more
> > > >
> > > >
> > > > Hi Nobu,
> > > >
> > > > Given this part of the exception, it seems it was unable to get a
> > > > connection to the database.  How is your connection pool configured?
> > Do
> > > > you only have one connection?
> > > >
> > > > mrg
> > > >
> > >
> >
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message