database concept help
I am altering a project (adding a relation) and I don't understand the Flatten relationship option. this will be a many to many. I just don't understand what flattening does. I started googling and so far the answers don't click. what's happening in a flattened vs an un-flattened relationship. Ted ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: database concept help
Le 2010-09-29 à 06:42, Theodore Petrosky a écrit : I am altering a project (adding a relation) and I don't understand the Flatten relationship option. this will be a many to many. I just don't understand what flattening does. I started googling and so far the answers don't click. what's happening in a flattened vs an un-flattened relationship. Flattened means that the table in the middle (that only holds the keys to join the two other tables) is hidden in the EOs, and when you create a new object in one of the two tables, the join table will automatically be populated. So let's say you have a People and a Job tables, and the join table is People_Job, to add a new job to a person, you do : aPerson.setRelationJob(newJob) No need to do aPerson.setRelationshipPeopleJob(new PeopleJob). ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: database concept help
so I am creating a little test. I have a People and a Job entity. attributes: People has a personName attribute and Job has a jobtitle I created the many to many selecting the Flatten Relationship option. I get a new entity: PeopleJob so far so good. I see in _Job.java a method: addToPeoplesRelationship but no 'set'. Was that a typo on your part? I am going to continue playing with my test app and see where it leads me. thanks for the help. Ted --- On Wed, 9/29/10, Pascal Robert prob...@macti.ca wrote: From: Pascal Robert prob...@macti.ca Subject: Re: database concept help To: Theodore Petrosky tedp...@yahoo.com Cc: webobjects-dev@lists.apple.com Date: Wednesday, September 29, 2010, 6:47 AM Le 2010-09-29 à 06:42, Theodore Petrosky a écrit : I am altering a project (adding a relation) and I don't understand the Flatten relationship option. this will be a many to many. I just don't understand what flattening does. I started googling and so far the answers don't click. what's happening in a flattened vs an un-flattened relationship. Flattened means that the table in the middle (that only holds the keys to join the two other tables) is hidden in the EOs, and when you create a new object in one of the two tables, the join table will automatically be populated. So let's say you have a People and a Job tables, and the join table is People_Job, to add a new job to a person, you do : aPerson.setRelationJob(newJob) No need to do aPerson.setRelationshipPeopleJob(new PeopleJob). ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: database concept help
Ted Conceptually, if the association entity (PeopleJob) is just that an association between the two EO's and no other attributes are on the the association then Flatten is good. However, if you have another attribute such as isPrimary on the PeopleJob or startDate then flatten would not be the right approach. Paul On Sep 29, 2010, at 9:14 AM, Theodore Petrosky wrote: so I am creating a little test. I have a People and a Job entity. attributes: People has a personName attribute and Job has a jobtitle I created the many to many selecting the Flatten Relationship option. I get a new entity: PeopleJob so far so good. I see in _Job.java a method: addToPeoplesRelationship but no 'set'. Was that a typo on your part? I am going to continue playing with my test app and see where it leads me. thanks for the help. Ted --- On Wed, 9/29/10, Pascal Robert prob...@macti.ca wrote: From: Pascal Robert prob...@macti.ca Subject: Re: database concept help To: Theodore Petrosky tedp...@yahoo.com Cc: webobjects-dev@lists.apple.com Date: Wednesday, September 29, 2010, 6:47 AM Le 2010-09-29 à 06:42, Theodore Petrosky a écrit : I am altering a project (adding a relation) and I don't understand the Flatten relationship option. this will be a many to many. I just don't understand what flattening does. I started googling and so far the answers don't click. what's happening in a flattened vs an un-flattened relationship. Flattened means that the table in the middle (that only holds the keys to join the two other tables) is hidden in the EOs, and when you create a new object in one of the two tables, the join table will automatically be populated. So let's say you have a People and a Job tables, and the join table is People_Job, to add a new job to a person, you do : aPerson.setRelationJob(newJob) No need to do aPerson.setRelationshipPeopleJob(new PeopleJob). ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/pyu%40mac.com This email sent to p...@mac.com ___ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
