Show child custom post types on single-{parent}.php?

Question

I'm very new to WordPress, and from the get-go I need to implement custom post types. Not sure I have all my WordPress marbles in one tin, so I'm asking for a bit of constructive criticism and above all patience.

I want something similar to this: http://wp-types.com/documentation/user-guides/creating-post-type-relationships/. More specifically, the car rental website part, but only customized for events and artists.

BUT, artists will be pre-specified and not added with an event, so I just want to maybe link them via checkbox, is this even possible?

To be specific, this is the scenario:

I have a site, which displays a load of events, each with a line up of artists. Now, I have created two (2) custom post types, Events & Artists. Events is a child of Posts, and Artists a child of Events.

I have already added 'Artist' posts in the post type. Artists should be able to be linked to multiple Events and Events should be able to have multiple Artists.

Answer 1

One post type can be the child of another post type: attachments for example are children of posts or pages. The association is described in the posts table in a field post_parent that holds a post ID.

But … what you want can be solved in many different ways. You don't have to use the post_parent field. I don't think that a simple hierarchy can reflect the relations between your objects. You need probably many-to-many relations, and these are not native to WordPress.

• One blog post or page can cover multiple events, multiple artists or both.
• One event can be associated with multiple artists and vice versa.

Possible solutions

• Create a custom taxonomy for artists and build a shadow custom post type for it to hold longer text information and attachments. Not easy to manage, the code gets messy very fast.
• Save the relationships in post meta data. Then have to decide which data are stored on which post, your queries will get very long and complicated.
• Use separate tables (one for relationships, one for meta data about these relationships). Requires good knowledge of the WordPress data base API, and you have to take special care to catch these tables in backups and export files.

Maybe the plugin Posts 2 Posts will help you. It uses two extra tables – which is (from my experience with similar situations) the fastest option.

See also this related post about a similar question.