Package com.db4o.internal.query.processor

Class QConstraints

    • Method Detail

      • contains

        public Constraint contains()
        Description copied from interface: Constraint
        Sets the evaluation mode to string contains comparison. This only works on strings. 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 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.

      • 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("Ferrari", pilot);
 container.store(car);
 Car otherCar = new Car("Ferrari", pilot);
 container.store(otherCar);
 Query query = container.query();
 query.constrain(Car.class);
 // All cars having pilot with the same database identity
 // will be retrieved.
 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.

      • not

        public Constraint not()
        Description copied from interface: Constraint
        Turns on not() comparison. All objects not full filling the constrain condition will be returned. For example:
         Pilot pilot = new Pilot("Test Pilot1", 100);
 container.store(pilot);
  ...
 query.constrain(Pilot.class);
 query.descend("name").constrain("t0").endsWith(true).not();

        Specified by:
        not in interface Constraint
        Overrides:
        not 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 is a contains comparison which is case insensitive. This only works on strings. 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 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 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 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.

      • 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.