Web Store Schema

[This is preliminary documentation and subject to change.]

The Web Store allows you to store data about content with the content itself, rather than having a separate database. You can also use Web Store items for just persisting data, rather than for content.

The schema operates differently than schema for Microsoft SQL Server and other relational databases. The schema is not for maintaining relational database integrity, and it does not provide constraints such as a primary key; rather, the Web Store schema provides the following capabilities:

• Creating a property with or without pre-defined schema.
• Persisting string values up to 50K and over.
• The means, achieved by defining content classes, to flexibly categorize properties in terms of their purpose and usage. A content class defines a set of properties.
• Attributing content classes to a folders and items, resulting in properties defined for those content classes appearing in folders and items so attributed.
• A mechanism for discovery of content class and property definitions by applications, including the Web Store SQL engine, the Web Forms architecture, and future Microsoft Office applications.

There is no requirement to use schema. You can simply add properties to an item, using the ADO Append method, specifying only a name and data type; however, these properties are lost if you remove the item.

Whether or not you define schema, a set of core properties exists for every item providing essential data processing information, such as the DAV:href property of an item’s URL.

A relational database, however, is still preferred for applications that require relational integrity such as a sales application that tracks customer orders and inventory. But for document management, workflow, and applications that do not require relational constraints—the Web Store provides a platform for quick and powerful application development.