The Entity Construction Kit (ECK) builds upon the entity system to create a flexible and extensible data modeling system both with a UI for site builders, and with useful abstractions (classes, plugins, etc) to help developers use entities with ease. ECK allows the creation and management of entity types with custom properties; adding bundles to entity types; and fields to bundles, with the help of the Field UI module. If that last sentence sounded like a foreign language, I suggest reading the first section of ECK's documentation: Understanding Entity Terminology A fairly recent video demonstrating ECK's capabilities was created by Shane at Code Karate: Drupal 7 Entity Construction Kit. This video should get most site builders going. An older summary on what ECK could do on 7.x-1.1-alpha3 can be found in Jeff Eaton's article: Module Monday: Entity Construction Kit.

This is a work in progress attempt to use a config-entity to define field-types that union together existing field types. Kind of like paragraphs or field collection, without the extra entity. Similar to multifield in D7, but backed by D8's typed-data. See The readme for what is working and where you can help. The tricky bits (the data-model) are done, the UI work (config entity UI, formatter, widget) is where the love is needed. Example of the data-model.

Always Clear the cache if you have problem with this module. One entity One table, keep your database table clean. Content Entity Builder, this module allow you build a content entity type by config and export it to module. Different from ECK module: this module does not support bundle this module does not support revision this module allow you add base field to entity by config, recommend way "One entity One table". I don't like the way: one field 2 tables, it is big waste.