Zotero stores bibliographic data in an internal SQLite database which can be accessed with the Zotero data API or with an external SQLite client. Knowledge of the data model is needed for Creating Translators for Sites (import) and for Creating Citation Styles (export).
Each bibliographic record in Zotero has an “item type” (book, journal article, thesis…), a set of fields (author, title, date…), and field values. The selection of fields depends on the item; for instance, a thesis has a “university” field which other items do not have.
Item types and fields are defined in system.sql and translated in zotero.properties. In theory you can change and add item types and fields, but this may make your installation of Zotero incompatible with other users and future releases—import routines and citation formats may not work anymore. If you need to add additional information to your records, you should use the “extra” field that is available for all item types. Zotero can be used in many languages, but you should always refer to item types and fields with their internal name as defined in system.sql and used in zotero.properties.
In addition to the basic item types and fields, each item can have associated user data as defined in userdata.sql. This includes:
- a set of notes
- a set of attachments
- a set of tags
- a set of links to related items
Up to now there is no full reference of item types, fields and user data—just try to find out using the user interface or dig into SQL!
The CSL syntax summary also contains some lists of fields.