db4o

Db4objects.Db4o.Query Namespace

Query package.

Namespace hierarchy

Classes

Class Description
Predicate Base class for native queries.

Interfaces

Interface Description
ICandidate candidate for Db4objects.Db4o.Query.IEvaluation callbacks.

During query execution all registered Db4objects.Db4o.Query.IEvaluation callback handlers are called with Db4objects.Db4o.Query.ICandidate proxies that represent the persistent objects that meet all other Db4objects.Db4o.Query.IQuery criteria.

A Db4objects.Db4o.Query.ICandidate provides access to the persistent object it represents and allows to specify, whether it is to be included in the Db4objects.Db4o.IObjectSet resultset.
IConstraint constraint to limit the objects returned upon query execution .

Constraints are constructed by calling Query.constrain() .

Constraints can be joined with the methods Db4objects.Db4o.Query.IConstraint.And and Db4objects.Db4o.Query.IConstraint.Or .

The methods to modify the constraint evaluation algorithm may be merged, to construct combined evaluation rules. Examples:
  • Constraint#smaller().equal()
    for "smaller or equal"
  • Constraint#not().like()
    for "not like"
  • Constraint#not().greater().equal()
    for "not greater or equal"
IConstraints set of Db4objects.Db4o.Query.IConstraint objects.

This extension of the Db4objects.Db4o.Query.IConstraint interface allows setting the evaluation mode of all contained Db4objects.Db4o.Query.IConstraint objects with single calls.

See also Db4objects.Db4o.Query.IQuery.Constraints .
IEvaluation for implementation of callback evaluations.
IQuery handle to a node in a S.O.D.A.
IQueryComparator Comparator for sorting queries on JDKs where java.util.Comparator is not available.

Delegates

Delegate Description
EvaluationDelegate