in reply to Re^2: OT: benefits of database normalization
in thread OT: benefits of database normalization
Nothing prevents you from adding a "Type" column to the second table to distinguish the two, if you need to. That way you may make the distinction if you want or treat them the same if you don't. Let's see the simplest query "find the description for this name, I don't know whether its a base name or an alias".
First design:
Second design:SELECT fact FROM Facts WHERE name = ? and Type = 1 UNION SELECT BaseFacts.fact FROM Facts as BaseFacts JOIN Facts as AliasFacts ON BaseFacts.fact_id = Convert(int,AliasFac +ts.data) WHERE AliasFacts.name = ? and AliasFacts.Type = 2 and BaseFacts.Type = 1 -- and this all works only if you do not ever have an alias to an alia +s!
Third design:SELECT fact FROM Facts WHERE name = ? UNION SELECT fact FROM Facts JOIN Aliases ON Aliases.fact_id = Facts.fact_id WHERE Aliases.name = ?
Which one do you like best? ;-)SELECT fact FROM Facts JOIN Names ON Names.Fact_id = Facts.fact_id WHERE Names.Name = ?
Jenda
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