public abstract class TupleTupleKeyCreator<E> extends TupleBase<E> implements SecondaryKeyCreator, ForeignKeyNullifier
TupleOutputobjects. The following abstract method must be implemented by a concrete subclass to create the index key using these objects
specified when opening the secondary database, the following method must be
overridden to nullify the foreign index key. If NULLIFY was not specified,
this method need not be overridden.
specified when creating the secondary, this method is called when the
entity for this foreign key is deleted. If NULLIFY was not specified,
this method will not be called and may always return false.
|Constructor and Description|
Creates a tuple-tuple key creator.
|Modifier and Type||Method and Description|
Creates a secondary key entry, given a primary key and data entry.
Creates the index key from primary key tuple and data tuple.
Sets the foreign key reference to null in the datum of the primary database.
Clears the index key in the tuple data entry.
entryToInput, getTupleBufferSize, getTupleOutput, inputToEntry, newOutput, newOutput, outputToEntry, setTupleBufferSize
public boolean createSecondaryKey(SecondaryDatabase db, DatabaseEntry primaryKeyEntry, DatabaseEntry dataEntry, DatabaseEntry indexKeyEntry)
A secondary key may be derived from the primary key, primary data, or a combination of the primary key and data. For secondary keys that are optional, the key creator method may return false and the key/data pair will not be indexed. To ensure the integrity of a secondary database the key creator method must always return the same result for a given set of input parameters.
db- the database to which the secondary key will be added. This parameter is passed for informational purposes but is not commonly used.
primaryKeyEntry- the primary key entry. This parameter must not be modified by this method.
dataEntry- the primary data entry. This parameter must not be modified by this method.
indexKeyEntry- the secondary key created by this method.
public boolean nullifyForeignKey(SecondaryDatabase db, DatabaseEntry dataEntry)
db- the database in which the foreign key integrity constraint is defined. This parameter is passed for informational purposes but is not commonly used.
dataEntry- the existing primary datum in which the foreign key reference should be set to null. This parameter should be updated by this method if it returns true.
public abstract boolean createSecondaryKey(TupleInput primaryKeyInput, TupleInput dataInput, TupleOutput indexKeyOutput)
public boolean nullifyForeignKey(TupleInput dataInput, TupleOutput dataOutput)
The secondary key should be output or removed by this method such
createSecondaryKey(com.sleepycat.db.SecondaryDatabase, com.sleepycat.db.DatabaseEntry, com.sleepycat.db.DatabaseEntry, com.sleepycat.db.DatabaseEntry) will return false. Other fields in the
data object should remain unchanged.
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