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From Michael Gentry <blackn...@gmail.com>
Subject Re: Aggregate function
Date Fri, 15 Jul 2016 14:49:31 GMT
Hi Nobu,

I have an AggregateUtils that I use:

https://github.com/mrg/cbe/tree/master/FetchingObjects/Aggregates/src/main/java/cbe/fetching/utilities

Here is an example of code using AggregateUtils:

https://github.com/mrg/cbe/blob/master/FetchingObjects/Aggregates/src/main/java/cbe/fetching/Aggregates.java

To use it for your example would be something like this:

SelectQuery query = new SelectQuery(Reading.class);
BigDecimal max = AggregateUtils.max(dataContext, query,
READING.READING_ID_PROPERTY);

On a side note, I'm guessing "reading_id" is your primary key?  If so, why
are you trying to get the maximum value for it?  Is the primary key/id not
being generated by the database?

mrg


On Fri, Jul 15, 2016 at 5:56 AM, Harunobu Oyama <ho@telensa.com> wrote:

> Hi,
>
> What is the Cayenne way to execute aggregate functions?
>
> For example, SELECT MAX("reading_id") FROM "reading" ?
>
> I tried passing SQLTemplate containing the SQL written above
> to performGenericQuery method, with no luck. Are we supposed to use JDBC?
> If so, what is the best way to get the JDBC Connection?
>
> Any hint would be appreciated.
>
> thank you,
> nobu
>

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