I'm considering using SQLObject for a new big project (and submitting
patches to make the tests pass under mysql), but I want to convince
myself that SQLObject would have worked for my old project first.
I built my own quasi-ORM (before I knew that ORM's existed) that allowed
a user to specify a filter on any column in the database, and the system
would join it into the query. All that needed to be specified was the
fields to query and a set of filters. The resulting query was something
like this:
SELECT DISTINCT
flows.FlowSubTarget, MAX(projects.FCassy) AS MAX, projects.IsRelease
FROM
files, names, projects, flows, values_i
WHERE
names.MetricType = 'i'
AND names.FlowId = flows.id
AND projects.id = files.ProjectId
AND projects.MaxMTime > DATE_SUB(NOW(), INTERVAL 10 DAY)
AND flows.FlowSubTarget RLIKE BINARY '^Sort.*(Stp|Setup)'
AND projects.Project = 'peach'
AND files.id = values_i.FileId
AND projects.FCassy >= 0
AND projects.Tapeout = 'sa15'
AND values_i.NameId = names.id
GROUP BY flows.FlowSubTarget, projects.IsRelease;
Note that the query returns values from various tables. The most
bothersome thing to me about ORM's is that they seem to only return data
from one specific table at a time. The code that generated this query
went something like the following. (Not exactly because parts were from
configuration files and parts were from previous queries, making the
whole thing dynamic).
q = db.select("FlowSubTarget", alias(max("FCassy"), "MAX"), "IsRelease")
q.filters(
MetricType = 'i',
Project = 'mario',
Tapeout = 'sa11'
)
q.add_filter(MaxMTime, ">", "DATE_SUB(NOW(), INTERVAL 10 DAY)")
q.add_filter(FlowSubTarget, "RLIKE BINARY", "'^Sort.*(Stp|Setup)'")
q.add_filter(FCassy, ">=", 0)
q.group_by("FlowSubTarget", "IsRelease")
print q
I understand that automatic joining like this is not generally a good
idea, but it's necessary in this case because the fields to filter are
not known till run time. The result is deterministic because the
database has no cycles (aka. tree topology).
My question is: Could I have used SQLObject to do this (reasonably)?
Thanks ahead of time for any light you can shed on this subject.
--Buck
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of
Sam's Lists
Sent: Sunday, August 17, 2008 3:46 AM
To: sqlobject-discuss
Subject: [SQLObject] Having a modified column filled in
automagically...
Hi...
I'd like to be able to create a timestamp column called "mtime"
in some of my columns. This would hold a timestamp of when the row was
last modified.
But I'd like the timestamp to be updated automatically whenever
sqlobject updates anything else in the row.
How can I do this? I'd like a solution that is easy to add to
any table....maybe so easy that the table only has to have a column
called mtime and then everything happens without anything extra on my
part.
Thanks
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