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From Kasper Sørensen <i.am.kasper.soren...@gmail.com>
Subject Re: New operator types. "<=" ">=" and "BETWEEN"
Date Wed, 17 Sep 2014 19:18:15 GMT
I am still a bit unsure about the BETWEEN operator. Partly because I've
never used it in any database myself :-) But I was also reading a bit about
it [1] and found that it is implemented differently in different databases
with regard to whether it includes or excludes the boundary values. For
this reason I would actually prefer using 2x "greater/less than" filter
items instead of a single "between" filter item. Our queries should have
the same meaning on all databases.

Another little thing I found is that "NOT BETWEEN" is also an option. We
might choose not to implement that, but just wanted to bring it to the
table. Sorry if I'm now just making it more complex :-P

2014-09-17 11:08 GMT+02:00 Francisco Javier Cano Bailen <fjcano@stratio.com>
:

> Hello,
>
> I performed some test and my first idea is:
>
> Manage operator field for BETWEEN operand as an array/list with size 2 (~
> to IN).
>
> I have developed a skeleton and I'm fixing some tests.
>
> Do you have other ideas?
>
> Regards,
>
> 2014-09-16 12:59 GMT+02:00 Kasper Sørensen <i.am.kasper.sorensen@gmail.com
> >:
>
> > Hi Francisco,
> >
> > These sound like cool additions in deed. I think you're right wrt. where
> > the impact would be.
> >
> > Would also need to check other modules that does smart things with query
> > optimizations, but that comes second.
> >
> > Not sure how to fix the BETWEEN case since FilterItem only takes one
> > operand. Any ideas?
> > Den 16/09/2014 11.52 skrev "Francisco Javier Cano Bailen" <
> > fjcano@stratio.com>:
> >
> > > Hello,
> > >
> > > Thanks Kasper for your first support.
> > >
> > > Regarding the OperatorType, MetaModel provides:
> > >
> > > EQUALS_TO("="), DIFFERENT_FROM("<>"), LIKE("LIKE"), GREATER_THAN(">"),
> > > LESS_THAN("<"), IN("IN"),
> > >
> > > If it is possible, I would like to implement "<=", ">="" and "BETWEEN"
> > > operator types.
> > >
> > > From my first review and test, I'm going to write new code in:
> > >
> > > FilterItem.java
> > > - toSql method
> > > - comparator method
> > > OperatorType.java
> > > - new OperatorType <= , >= and BETWEEN
> > > Query.java
> > > - BETWEEN operator syntax is BETWEEN X AND Y => manage Y operand
> without
> > > operator
> > >
> > > From your point of view, Do you have other ideas in mind?
> > >
> > > Regards,
> > >
> > > --
> > >
> > > Francisco Javier Cano
> > > Senior Developer
> > >
> > >
> > > <http://www.stratio.com/>
> > > Avenida de Europa, 26. Ática 5. 3ª Planta
> > > 28224 Pozuelo de Alarcón, Madrid
> > > Tel: +34 91 352 59 42 // *@stratiobd <https://twitter.com/StratioBD>*
> > >
> >
>
>
>
> --
>
> Francisco Javier Cano
> Senior Developer
>
>
> <http://www.stratio.com/>
> Avenida de Europa, 26. Ática 5. 3ª Planta
> 28224 Pozuelo de Alarcón, Madrid
> Tel: +34 91 352 59 42 // *@stratiobd <https://twitter.com/StratioBD>*
>

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