Re: Table design issue....
От | Josh Berkus |
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Тема | Re: Table design issue.... |
Дата | |
Msg-id | web-70284@davinci.ethosmedia.com обсуждение исходный текст |
Ответ на | Table design issue.... (pierre@kahuna.versions.com) |
Ответы |
Re: Table design issue....
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Список | pgsql-sql |
Pierre, > Ideas? Comments? Suggestions? Am I being crazy? Yes. To be blunt, you've picked one of the worst possible database designs for any useful purpose. This is, however, a common mistake as far too many books and training courses teach how to write SQL without teaching how to design a database. What you really want is something like this: CREATE TABLE tables (tableid CHAR(1) NOT NULL PRIMARY KEY); CREATE TABLE attributes (tableid CHAR(1) NOT NULL REFERENCES tables(tableid),attributeid CHAR(1) NOT NULL,CONSTRAINT tab_attr_PKPRIMARY KEY (tableid, attributeid) ); This makes your select statement possible:SELECT tableid FROM attributes WHERE attributeid = 'C'GROUP BY tableid ORDER BYtableid; If your application requirements are more complicated than this, you need to either: a) hire a relational design expert, or b) become one. Books I'd recommend for the latter are Database Design for Mere Mortals and Practical Issues in Database Design (F. Pascal). -Josh Berkus ______AGLIO DATABASE SOLUTIONS___________________________ Josh Berkus Complete informationtechnology josh@agliodbs.com and data management solutions (415) 565-7293 for law firms, small businesses fax 621-2533 and non-profit organizations. San Francisco
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