First Entity Class And Entity

This basic level tutorial guides you through creating an entity class and an entity.

Adding Entity Classes

You need to have an empty Spine database to work through this short tutorial. Open Spine Toolbox, select File -> New DB Editor to open the Database editor. Then, click the New button on the toolbar or select File->New… to create a fresh database. Choose a folder that is easy remember and give the database a descriptive name, such as Spine-tutorial.sqlite. It might be a good idea to keep the database around as it will be needed in other tutorials.

First, we need some entity classes. Entity classes are structural data that define the types of entities in the database. Each type has a distinct set of parameters given by the parameter definitions of the class.

Let’s add an entity class to called Fish to the database. Right-click the root item on Entity tree to open the entity context menu and select Add entity classes… This opens a dialog with a table. The table can be filled with new classes by hand or by copy-pasting data from e.g. spreadsheet program. Write Fish to the entity class name column. You can also write a description and choose a suitable icon and color for the class. The rest of the columns can be left as-is for now. The classes defined in the table are added when you press Ctrl+Enter or click Ok.

Often, you do not need to create classes manually. Instead, the classes may come from a tool provided by the model you are using. For example, the SpineOpt plugin “Load template” populates the database with all classes required by SpineOpt.

Adding Entities

Entities are instances of the class with individual values for the parameters of the class. With the Fish class in place, we can finally add some fish to our database! Which famous fish come to your mind?

Next, we will add Nemo to the database. Click the icon next to the Fish class in Entity tree or right-click Fish and select Add entities…. An Add entities dialog opens that works very similarly to the Add Entity classes dialog we used previously. Here, write Nemo to the entity name column and press Ctrl+Enter to accept the addition. We have our first entity!

Committing Changes

At this point it is a good idea to save our achievements. This operation is called *committing* since Spine data is stored in an SQL database. In case of file-backed databases like SQLite, the operation is pretty much like saving changes to a file.

Press Ctrl+Enter or click the Commit button on the toolbar at the top. You are asked to provide a commit message before proceeding. Write something like:

Added Fish class and first fish, Nemo.

and press Ctrl+Enter to accept, or click Commit. This stores pending changes to the database.

Past commit messages can viewed from Session->History… which opens the Commit viewer dialog. Selecting a commit from the dialog also displays affected items. However, the dialog can only show the latest action (addition or update) for an item due to limitations on how the commit data is stored. Deleted items will not show in affected items at all.

Next Steps

This tutorial continues on First Parameter where we will expand the dataset by adding a parameter to the Fish class.