From: Dmitry Turin <sql4-en@narod.ru>
To: pgsql-sql@postgresql.org
Subject: Re: We all are looped on Internet: request + transport = invariant
Date: Tue, 24 Apr 2007 15:31:33 +0300
Message-ID: <7519129062.20070424153133@narod.ru> (raw)
In-Reply-To: <1177414707.737.69.camel@pampa>
References: <14110647859.20070413105812@narod.ru>
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<1684192906.20070419090827@narod.ru>
<20070419134808.GB14187@phlogiston.dyndns.org>
<814860828.20070420120819@narod.ru>
<4628A08F.9050804@archonet.com>
<1177072978.760.40.camel@pampa>
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<1312216062.20070423112045@narod.ru>
<1177329421.737.39.camel@pampa>
<922322078.20070424105126@narod.ru>
<1177414707.737.69.camel@pampa>
Good day, Joe.
J> "Fictional" is IMO not a good choice for
J> describing aggregates, because it means "a story that is not true",
J> whereas an SQL aggregate is something that is "true" (in the
J> mathematical sense) but is "derived" from other values.
It means, that TML and DDL aggregates have different sense.
J> (I'm not sure what the special symbols mean -- maybe what you need first
J> is a syntax reference for TML)
http://sql4.by.ru/site/sql40/en/author/tree_eng.htm
J> sum of the employees salaries?
yes.
"amount" is quantity of employees
J> How do I see employees in just one department?
department[id="1"].employee >>;
or
department[name="Technical"].employee >>;
J> How do I see a single employee?
employee[id="31"] >>;
or
employee[name="Tomson"] >>;
-- maybe several employee with surname Tomson
J> How do I see all employees that have a salary greater than 3500
department.employee[salary>3500] >>;
J> ordered by their names?
Now sorting for output is absent.
I'm not sure, that it's necessary,
but i already thought about this and continue to think.
J> How do I actually retrieve SUM(salary)
Declare field "sum" as not fictional.
You can always declare field "sum" as not fictional and
put sign "#" before field to prevent output of field.
J> GROUP BY department?
It is always "group by", because it is field of record "department"
P.S.
If you don't like to put sign "#" before field "sum",
or you don't like absence of sorting NOW
(it's possible, that i add sorting),
then remember, that advantage is absence of gasket
(php, etc) between DBMS and external world.
That is more important for un-experienced users.
Dmitry Turin
http://html6.by.ruhttp://sql4.by.ruhttp://computer2.by.ru
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To: pgsql-sql@postgresql.org
Cc: sql4-en@narod.ru
Subject: Re: We all are looped on Internet: request + transport = invariant
In-Reply-To: <7519129062.20070424153133@narod.ru>
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