User database objects are the objects your code works with
the most, from a given Session.
The following diagram illustrates the types of objects you
use to access a user database and the relationships between them. The arrows
indicate the direction in which you acquire related objects. For example,
from the Session object, you can acquire different types of objects such as
DatabaseDesc, Entity, EntityDef, QueryDef, and ResultSet directly.
In some cases, objects have an indirect relationship. For
example, the QueryDef and ResultSet objects work together to run a query,
but you create these objects separately using methods of the Session object.
The ResultSet object uses information from the QueryDef object to perform
the query.
- User database object
- Description
- Session Object
- Access the user database; build a new record
- Entity Object
- An object corresponding to a database record. Work with
Record data: set field values, validate, commit, revert.
- EntityDef Object
- View read-only meta-data: actions, fields, hooks, states,
and transitions applicable to a given record type
- EntityDefs Object
- Collection of EntityDef (record type) objects
- QueryDef Object
- Defines the query criteria.
- ResultSet Object
- Contains the data the query fetches
- QueryFilterNode
Object
- Implements comparison filters for the query
A QueryDef is the definition of a query.
A ResultSet is the result of a query. There are two steps:
- First, the result set is created from a QueryDef (this
is like compiling the query).
- Next, the result set is executed to get actual results.
If it is a parameterized query, then the ResultSet is used to fill in values
for the queries.