org.h2.result

Class SortOrder

java.lang.Object

org.h2.result.SortOrder

All Implemented Interfaces:

Comparator<Value[]>

public class SortOrder
extends Object
implements Comparator<Value[]>

A sort order represents an ORDER BY clause in a query.

Field Summary

Fields

Modifier and Type	Field and Description
static int	ASCENDING This bit mask means the values should be sorted in ascending order.
static int	DESCENDING This bit mask means the values should be sorted in descending order.
static int	NULLS_FIRST This bit mask means NULLs should be sorted before other data, no matter if ascending or descending order is used.
static int	NULLS_LAST This bit mask means NULLs should be sorted after other data, no matter if ascending or descending order is used.

Constructor Summary

Constructors

Constructor and Description
SortOrder(Database database, int[] index, int[] sortType) Construct a new sort order object.

Method Summary

Methods

Modifier and Type	Method and Description
int	compare(Value[] a, Value[] b) Compare two expression lists.
static int	compareNull(boolean aNull, boolean bNull, int sortType) Compare two expressions where one of them is NULL.
int[]	getIndexes() Get the column index list.
int[]	getSortTypes() Get the sort order bit masks.
String	getSQL(Expression[] list, int visible) Create the SQL snippet that describes this sort order.
void	sort(ArrayList<Value[]> rows) Sort a list of rows.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

equals

Field Detail

ASCENDING

public static final int ASCENDING

This bit mask means the values should be sorted in ascending order.

See Also:

Constant Field Values

DESCENDING

public static final int DESCENDING

This bit mask means the values should be sorted in descending order.

See Also:

Constant Field Values

NULLS_FIRST

public static final int NULLS_FIRST

This bit mask means NULLs should be sorted before other data, no matter if ascending or descending order is used.

See Also:

Constant Field Values

NULLS_LAST

public static final int NULLS_LAST

This bit mask means NULLs should be sorted after other data, no matter if ascending or descending order is used.

See Also:

Constant Field Values

Constructor Detail

SortOrder

public SortOrder(Database database,
         int[] index,
         int[] sortType)

Construct a new sort order object.

Parameters:

database - the database

index - the column index list

sortType - the sort order bit masks

Method Detail

getSQL

public String getSQL(Expression[] list,
            int visible)

Create the SQL snippet that describes this sort order. This is the SQL snippet that usually appears after the ORDER BY clause.

Parameters:

list - the expression list

visible - the number of columns in the select list

Returns:

the SQL snippet

compareNull

public static int compareNull(boolean aNull,
              boolean bNull,
              int sortType)

Compare two expressions where one of them is NULL.

Parameters:

aNull - whether the first expression is null

bNull - whether the second expression is null

sortType - the sort bit mask to use

Returns:

the result of the comparison (-1 meaning the first expression should appear before the second, 0 if they are equal)

compare

public int compare(Value[] a,
          Value[] b)

Compare two expression lists.

Specified by:

compare in interface Comparator<Value[]>

Parameters:

a - the first expression list

b - the second expression list

Returns:

the result of the comparison

sort

public void sort(ArrayList<Value[]> rows)

Sort a list of rows.

Parameters:

rows - the list of rows

getIndexes

public int[] getIndexes()

Get the column index list.

Returns:

the list

getSortTypes

public int[] getSortTypes()

Get the sort order bit masks.

Returns:

the list