Datamapper DataMapper

Comments and changes to this ticket

• 

  Dan Kubb (dkubb) October 28th, 2008 @ 12:43 AM

  • State changed from “new” to “invalid”

  The :field property option is a String because it's not the same thing as :child_key.

  The :field is the name of the container holding the property value in the storage engine. In the case of an RDBMS, the field would be equivalent to the table's column name. By default the :field is the same as the stringified property name, but it can be overridden in case you're using a legacy DB, or columns need special names (like CouchDB).

  The :child_key is the Array of property names to join with on the child side of the association. In a belongs_to() association, the child is the current model and the parent is the model the current one belongs to. It is an Array because a model's key can be one or more properties.

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  Dan Kubb (dkubb) October 28th, 2008 @ 01:49 PM

  If I understand you correctly, you're saying the :child_key=>[:supplier_id] bit is referring to another property in my model, and not directly to a table's column name? Even if such a property has not been explicitly defined in my model?

  That's correct. The option :child_key => [ :supplier_id ] instructs the belongs_to method to create a property named :supplier_id inside the current model and use that to connect to the parent model, which in this case is Organization because you specified the :class_name option.