Thread: Database normalization
Is this model (Symfony's YML based) wrong based on normalization?
The full discussion can be found at http://www.symfony-project.org/forum/index.php/t/12807/
All I want is the best option, but not based in common sense, but in rules, cause after a lot of discussions I found this way better than the usual one.
propel:
client:
client_id: {type: integer}
foo:
client_id: {type: integer, foreignTable: client, foreignReference: client_id}
foo_id: {type: integer}
bar:
client_id: {type: integer, foreignTable: client, foreignReference: client_id}
bar_id: {type: integer}
foobar:
client_id: {type: integer}
foo_id: {type: integer}
bar_id: {type: integer}
_foreignKeys:
fk_foo:
foreignTable: foo
references:
- { local: client_id, foreign: client_id }
- { local: foo_id, foreign: foo_id }
fk_bar:
foreignTable: bar
references:
- { local: client_id, foreign: client_id }
- { local: bar_id, foreign: bar_id }
The full discussion can be found at http://www.symfony-project.org/forum/index.php/t/12807/
All I want is the best option, but not based in common sense, but in rules, cause after a lot of discussions I found this way better than the usual one.
Sid 'Neko Tamashii' wrote: > Is this model (Symfony's YML based) wrong based on normalization? > > propel: >> client: >> client_id: {type: integer} >> >> foo: >> client_id: {type: integer, foreignTable: client, foreignReference: client_id} >> foo_id: {type: integer} >> >> bar: >> client_id: {type: integer, foreignTable: client, foreignReference: client_id} >> bar_id: {type: integer} Well, assuming the primary-key on these includes both columns - e.g. (client_id,foo_id) >> >> foobar: >> client_id: {type: integer} >> foo_id: {type: integer} >> bar_id: {type: integer} >> _foreignKeys: >> fk_foo: >> foreignTable: foo >> references: >> - { local: client_id, foreign: client_id } >> - { local: foo_id, foreign: foo_id } >> fk_bar: >> foreignTable: bar >> references: >> - { local: client_id, foreign: client_id } >> - { local: bar_id, foreign: bar_id } This looks fine (assuming not-null on all columns). You could make an argument for an explicit foreign-key for client_id too, but it's clearly safe not to have one while the other two foreign-keys are there. If you allow client_id to be set separately from foo_id/bar_id then you'll want the foreign-key of course. The one thing I would do is change the names of foo_id, bar_id since they're not identifiers by themselves. -- Richard Huxton Archonet Ltd
To be more clear:<br /><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt0pt 0.8ex; padding-left: 1ex;">client:<br /> id: {type: integer}<br /><br />users:<br /> user_id: {type: integer, primaryKey:true,foreignTable: client, foreignReference: id}<br /> id: {type: integer}<br /><br />profiles:<br /> client_id:{type: integer, primaryKey:true, foreignTable: client, foreignReference: id}<br /> id: {type: integer}<br /><br/>userprofile:<br /> client_id: {type: integer, primaryKey:true}<br /> user_id: {type: integer, primaryKey:true}<br/> profile_id: {type: integer, primaryKey:true}<br /> _foreignKeys:<br /> fk_user:<br /> foreignTable:users<br /> references:<br /> - { local: client_id, foreign: client_id }<br /> - { local:user_id, foreign: id }<br /> fk_profile:<br /> foreignTable: profile<br /> references:<br /> -{ local: client_id, foreign: client_id }<br /> - { local: profile_id, foreign: id }<br /></blockquote><br />Eachclient has it's own profiles and users, and each user has some profiles<br />The idea is to enforce the value of client_idto be the same at all moments<br /><br /><div class="gmail_quote">On Tue, May 6, 2008 at 9:28 AM, Richard Huxton<<a href="mailto:dev@archonet.com">dev@archonet.com</a>> wrote:<br /><blockquote class="gmail_quote" style="border-left:1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="Ih2E3d">Sid 'NekoTamashii' wrote:<br /><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); padding-left:1ex;"> Is this model (Symfony's YML based) wrong based on normalization?<br /><br /> propel:<br /><blockquoteclass="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> client:<br /> client_id: {type: integer}<br /><br /> foo:<br /> client_id: {type: integer, foreignTable: client, foreignReference:client_id}<br /> foo_id: {type: integer}<br /><br /> bar:<br /> client_id: {type: integer, foreignTable:client, foreignReference: client_id}<br /> bar_id: {type: integer}<br /></blockquote></blockquote><br /></div>Well, assuming the primary-key on these includes both columns - e.g. (client_id,foo_id)<div class="Ih2E3d"><br /><br/><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><blockquoteclass="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><br /> foobar:<br/> client_id: {type: integer}<br /> foo_id: {type: integer}<br /> bar_id: {type: integer}<br /> _foreignKeys:<br/> fk_foo:<br /> foreignTable: foo<br /> references:<br /> - { local: client_id,foreign: client_id }<br /> - { local: foo_id, foreign: foo_id }<br /> fk_bar:<br /> foreignTable:bar<br /> references:<br /> - { local: client_id, foreign: client_id }<br /> - { local:bar_id, foreign: bar_id }<br /></blockquote></blockquote><br /></div> This looks fine (assuming not-null on all columns).<br/><br /> You could make an argument for an explicit foreign-key for client_id too, but it's clearly safe notto have one while the other two foreign-keys are there. If you allow client_id to be set separately from foo_id/bar_idthen you'll want the foreign-key of course.<br /><br /> The one thing I would do is change the names of foo_id,bar_id since they're not identifiers by themselves.<br /><font color="#888888"><br /> -- <br /> Richard Huxton<br/> Archonet Ltd<br /></font></blockquote></div><br />