org.apache.derby.impl.sql.execute
Class UniqueIndexSortObserver

java.lang.Object
  org.apache.derby.impl.sql.execute.BasicSortObserver
      org.apache.derby.impl.sql.execute.UniqueIndexSortObserver

All Implemented Interfaces:

SortObserver

 class UniqueIndexSortObserver
extends BasicSortObserver

Unique index aggregator. Enforces uniqueness when creating a unique index or constraint.

Field Summary

private java.lang.String	indexOrConstraintName
private boolean	isConstraint
private java.lang.String	tableName

Fields inherited from class org.apache.derby.impl.sql.execute.BasicSortObserver

distinct, doClone

Constructor Summary

UniqueIndexSortObserver(boolean doClone, boolean isConstraint, java.lang.String indexOrConstraintName, ExecRow execRow, boolean reuseWrappers, java.lang.String tableName)

Method Summary

DataValueDescriptor[]

insertDuplicateKey(DataValueDescriptor[] in, DataValueDescriptor[] dup) Called prior to inserting a duplicate sort key.

Methods inherited from class org.apache.derby.impl.sql.execute.BasicSortObserver

addToFreeList, getArrayClone, insertNonDuplicateKey

Methods inherited from class java.lang.Object

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

Field Detail

isConstraint

private boolean isConstraint

indexOrConstraintName

private java.lang.String indexOrConstraintName

tableName

private java.lang.String tableName

Constructor Detail

UniqueIndexSortObserver

public UniqueIndexSortObserver(boolean doClone,
                               boolean isConstraint,
                               java.lang.String indexOrConstraintName,
                               ExecRow execRow,
                               boolean reuseWrappers,
                               java.lang.String tableName)

Method Detail

insertDuplicateKey

public DataValueDescriptor[] insertDuplicateKey(DataValueDescriptor[] in,
                                                DataValueDescriptor[] dup)
                                         throws StandardException

Description copied from class: BasicSortObserver

Called prior to inserting a duplicate sort key.

Specified by:

insertDuplicateKey in interface SortObserver

Overrides:

insertDuplicateKey in class BasicSortObserver

Parameters:

in - the current row that the sorter is on the verge of retaining. It is a duplicate of existingRow.

dup - the row that is already in the the sorter which is a duplicate of insertRow

Returns:

the row to be inserted by the sorter. If null, then nothing is inserted by the sorter. Distinct sorts will want to return null.

Throws:

StandardException - Thrown on failure

See Also:

AggregateSortObserver.insertDuplicateKey(org.apache.derby.iapi.types.DataValueDescriptor[], org.apache.derby.iapi.types.DataValueDescriptor[])