Re: [Sqlalchemy-users] Re: Retrofitting database back end

[Jonathan Hayward http://JonathansCorner.com]

On 3/26/06, Jonathan Ellis <[EMAIL PROTECTED]> wrote:

On 3/25/06, Jonathan Hayward http://JonathansCorner.com <[EMAIL PROTECTED] > wrote:

A few questions:

1: How do I specify a string of indeterminate length in the pseudocode
at the bottom of this list? It will be a usability bug if I set
arbitrary limits on how long things can be?

Just don't specify a length with your String object.

Thanks.

2: What is the best way to store a list of strings as a field in a
database? (If need be I can have a delimiter-separated string, but I
want to know if there is a better method.)

You need a one-to-many join.

So you've got a sections table and you want a list of patterns to accept and one of patterns to deny, so you need a section_patterns_to_accept table that references sections and has a single text field.  Same for _to_deny.

Clumsy, but at least SA can turn these into lists for you at the mapper level.

Ok, as dealt with in the "Basic Data Mapping" section?

My pseudocode is below; I want to be able to access a pseudocode SQL
of "Select all documents [in the following section] containing 1 or
more occurrences of words X, Y, and Z and order them by date last
seen."

Well, if this is a toy app, your approach will be fine.  Otherwise you'll probably want to use a database with built-in full text search like postgresql's tsearch2.

Does Mysql have this search? The usage I illustrated above is a stable usage pattern (I'm not designing something from scratch, but trying to retrofit an existing application with custom database for better performance.

--
Jonathan Ellis
http://spyced.blogspot.com

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