com.db4o.internal.query.processor

Class QConObject

java.lang.Object

com.db4o.internal.query.processor.QCon

com.db4o.internal.query.processor.QConObject

All Implemented Interfaces:

Visitor4, Constraint, Unversioned

Direct Known Subclasses:

QConClass

public class QConObject
extends QCon

Object constraint on queries

Field Summary

Fields inherited from class com.db4o.internal.query.processor.QCon

_children, i_evaluator, i_parent

Constructor Summary

Constructors

Constructor and Description
QConObject()
QConObject(Transaction a_trans, QCon a_parent, QField a_field, java.lang.Object a_object)

Method Summary

Methods

Modifier and Type	Method and Description
Constraint	byExample() set the evaluation mode to object comparison (query by example).
boolean	canBeIndexLeaf()
boolean	canLoadByIndex()
Constraint	contains() sets the evaluation mode to string contains comparison.
Constraint	endsWith(boolean caseSensitive) sets the evaluation mode to string endsWith comparison.
Constraint	equal() Used in conjunction with Constraint.smaller() or Constraint.greater() to create constraints like "smaller or equal", "greater or equal".
QField	getField()
java.lang.Object	getObject() returns the Object the query graph was constrained with to create this Constraint.
Constraint	greater() sets the evaluation mode to >.
boolean	hasObjectInParentPath(java.lang.Object obj)
Constraint	identity() sets the evaluation mode to identity comparison.
int	identityID()
Constraint	like() sets the evaluation mode to "like" comparison.
boolean	onSameFieldAs(QCon other)
Constraint	smaller() sets the evaluation mode to <.
Constraint	startsWith(boolean caseSensitive) sets the evaluation mode to string startsWith comparison.
java.lang.String	toString()
void	visit(java.lang.Object obj)

Methods inherited from class com.db4o.internal.query.processor.QCon

and, childrenCount, container, evaluator, hasChildren, hasJoins, hasParent, id, internalSetProcessedByIndex, iterateChildren, iterateJoins, not, or, parent, processedByIndex, setCandidates, setProcessedByIndex, streamLock, transaction

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

QConObject

public QConObject()

QConObject

public QConObject(Transaction a_trans,
          QCon a_parent,
          QField a_field,
          java.lang.Object a_object)

Method Detail

canBeIndexLeaf

public boolean canBeIndexLeaf()

Overrides:

canBeIndexLeaf in class QCon

canLoadByIndex

public boolean canLoadByIndex()

Overrides:

canLoadByIndex in class QCon

getField

public QField getField()

Overrides:

getField in class QCon

hasObjectInParentPath

public boolean hasObjectInParentPath(java.lang.Object obj)

Overrides:

hasObjectInParentPath in class QCon

identityID

public int identityID()

Overrides:

identityID in class QCon

onSameFieldAs

public boolean onSameFieldAs(QCon other)

Overrides:

onSameFieldAs in class QCon

visit

public void visit(java.lang.Object obj)

Specified by:

visit in interface Visitor4

Overrides:

visit in class QCon

contains

public Constraint contains()

Description copied from interface: Constraint

sets the evaluation mode to string contains comparison. The contains comparison is case sensitive. For example:
Pilot pilot = new Pilot("Test Pilot1", 100);
container.store(pilot);
...
query.constrain(Pilot.class);
// All pilots with the name containing "est" will be retrieved
query.descend("name").constrain("est").contains();

Specified by:

contains in interface Constraint

Overrides:

contains in class QCon

Returns:

this Constraint to allow the chaining of method calls.

See Also:

like() for case insensitive string comparison

equal

public Constraint equal()

Description copied from interface: Constraint

Used in conjunction with Constraint.smaller() or Constraint.greater() to create constraints like "smaller or equal", "greater or equal". For example:
query.constrain(Pilot.class);
query.descend("points").constrain(101).smaller().equal();
will return all pilots with points <= 101.

Specified by:

equal in interface Constraint

Overrides:

equal in class QCon

Returns:

this Constraint to allow the chaining of method calls.

getObject

public java.lang.Object getObject()

Description copied from interface: Constraint

returns the Object the query graph was constrained with to create this Constraint.

Specified by:

getObject in interface Constraint

Overrides:

getObject in class QCon

Returns:

Object the constraining object.

greater

public Constraint greater()

Description copied from interface: Constraint

sets the evaluation mode to >. For example:
query.constrain(Pilot.class);
query.descend("points").constrain(101).greater()
will return all pilots with points > 101.

Specified by:

greater in interface Constraint

Overrides:

greater in class QCon

Returns:

this Constraint to allow the chaining of method calls.

identity

public Constraint identity()

Description copied from interface: Constraint

sets the evaluation mode to identity comparison. In this case only objects having the same database identity will be included in the result set. For example:
Pilot pilot = new Pilot("Test Pilot1", 100);
Car car = new Car("BMW", pilot);
container.store(car);
// Change the name, the pilot instance stays the same
pilot.setName("Test Pilot2");
// create a new car
car = new Car("Ferrari", pilot);
container.store(car);
Query query = container.query();
query.constrain(Car.class);
// All cars having pilot with the same database identity
// will be retrieved. As we only created Pilot object once
// it should mean all car objects
query.descend("_pilot").constrain(pilot).identity();

Specified by:

identity in interface Constraint

Overrides:

identity in class QCon

Returns:

this Constraint to allow the chaining of method calls.

byExample

public Constraint byExample()

Description copied from interface: Constraint

set the evaluation mode to object comparison (query by example).

Specified by:

byExample in interface Constraint

Overrides:

byExample in class QCon

Returns:

this Constraint to allow the chaining of method calls.

like

public Constraint like()

Description copied from interface: Constraint

sets the evaluation mode to "like" comparison. This mode will include all objects having the constrain expression somewhere inside the string field. For example:
Pilot pilot = new Pilot("Test Pilot1", 100);
container.store(pilot);
...
query.constrain(Pilot.class);
// All pilots with the name containing "est" will be retrieved
query.descend("name").constrain("est").like();

Specified by:

like in interface Constraint

Overrides:

like in class QCon

Returns:

this Constraint to allow the chaining of method calls.

smaller

public Constraint smaller()

Description copied from interface: Constraint

sets the evaluation mode to <. For example:
query.constrain(Pilot.class);
query.descend("points").constrain(101).smaller()
will return all pilots with points < 101.

Specified by:

smaller in interface Constraint

Overrides:

smaller in class QCon

Returns:

this Constraint to allow the chaining of method calls.

startsWith

public Constraint startsWith(boolean caseSensitive)

Description copied from interface: Constraint

sets the evaluation mode to string startsWith comparison. For example:
Pilot pilot = new Pilot("Test Pilot0", 100);
container.store(pilot);
...
query.constrain(Pilot.class);
query.descend("name").constrain("Test").startsWith(true);

Specified by:

startsWith in interface Constraint

Overrides:

startsWith in class QCon

Parameters:

caseSensitive - comparison will be case sensitive if true, case insensitive otherwise

Returns:

this Constraint to allow the chaining of method calls.

endsWith

public Constraint endsWith(boolean caseSensitive)

Description copied from interface: Constraint

sets the evaluation mode to string endsWith comparison. For example:
Pilot pilot = new Pilot("Test Pilot0", 100);
container.store(pilot);
...
query.constrain(Pilot.class);
query.descend("name").constrain("T0").endsWith(false);

Specified by:

endsWith in interface Constraint

Overrides:

endsWith in class QCon

Parameters:

caseSensitive - comparison will be case sensitive if true, case insensitive otherwise

Returns:

this Constraint to allow the chaining of method calls.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object