I am not familiar with breeding business. My suggestion comes from a very different problem that i solved recently. The challenge was to describe a tree and to find the path to the root starting from any leaf or intermediate node. How to do? 1) The entity supported by the node shall support at least one relative precedence criterion which depends on the nature of the entity. Then we can specify a Node_Table(Node Primary Key,........,PrecedenceCriterion) 2) Populate the Node_Table (at least 2 linkable nodes at starting time) 3) Complete the links using a selection filter mainly based on precedence (we assume that the user has the expertise to pick the right choice) 4) Repeat 2) and 3) as far as necessary If only one-to-one links are required they can be included in the Node_Table model. If one-to-several links are necessary a separate Link_Table(LinkType,OwnerNode,LinkedNode) is recommended. (for example Link types may be Father,Mother,Clone)
John Machin a écrit : > On 5/06/2009 5:27 PM, Francis GAYREL wrote: > >> To build a consistent oriented tree we need to associate to the nodes a >> ranking property such as the birthdate (or any precedence criterion). >> Therefore the ancestor of someone is to be selected among older ones. >> > > "Ancestor" is a *derived* relationship, not something you'd wish to > store in the database, and is quite irrelevant at data-entry time. Don't > you mean "parent"? > > Let me get this straight: the user is entering the details of animal X > who was born yesterday and has to input somehow the identity of the > mother and of the father. > > >> To make the ancestor allocation more easy the ancestor's list may be >> filtered on birthdate credibility. >> > > So your plot is, (e.g. for the father) to show a list of all male > animals who are in some credible-parenthood age range on (say) a > drop-down list, and the user selects one, hopefully not at random. Is > that right? > > I would imagine in a planned targeted organised animal breeding program > that the mother-to-be and father-to-be are recorded at the time of > impregnation, and the identities are established from ear-tags, embedded > chips, photographs, etc and the credible-parenthood test is applied then > [note: test, NOT input selection method] and all of the above is > confirmed at birth. > > >> The ranking property eliminates the circular link concern. >> > > Indeed, but you have to use it properly to eliminate other data > integrity concerns :-) > > HTH, > > John > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
