Package org.h2.result

Class SortOrder

java.lang.Object

org.h2.result.SortOrder

All Implemented Interfaces:

java.util.Comparator<Value[]>

public final class SortOrder
extends java.lang.Object
implements java.util.Comparator<Value[]>

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

Field Summary

Fields

Modifier and Type	Field	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.
private java.util.ArrayList<QueryOrderBy>	orderList	The order list.
private int[]	queryColumnIndexes	The column indexes of the order by expressions within the query.
private SessionLocal	session
private int[]	sortTypes	The sort type bit mask (DESCENDING, NULLS_FIRST, NULLS_LAST).

Constructor Summary

Constructors

Constructor	Description
SortOrder(SessionLocal session, int[] queryColumnIndexes)	Construct a new sort order object with default sort directions.
SortOrder(SessionLocal session, int[] queryColumnIndexes, int[] sortType, java.util.ArrayList<QueryOrderBy> orderList)	Construct a new sort order object.

Method Summary

Modifier and Type	Method	Description
static int[]	addNullOrdering(Database database, int[] sortTypes)	Add explicit NULLS_FIRST or NULLS_LAST where they aren't already specified.
int	compare(Value[] a, Value[] b)	Compare two expression lists.
Column	getColumn(int index, TableFilter filter)	Get the column for the given table filter, if the sort column is for this filter.
java.util.ArrayList<QueryOrderBy>	getOrderList()	Returns the original query order list.
int[]	getQueryColumnIndexes()	Get the column index list.
java.util.Comparator<Value>	getRowValueComparator()	Returns comparator for row values.
int[]	getSortTypes()	Get the sort order bit masks.
int[]	getSortTypesWithNullOrdering()	Returns sort order bit masks with NULLS_FIRST or NULLS_LAST explicitly set.
java.lang.StringBuilder	getSQL(java.lang.StringBuilder builder, Expression[] list, int visible, int sqlFlags)	Create the SQL snippet that describes this sort order.
void	sort(java.util.ArrayList<Value[]> rows)	Sort a list of rows.
void	sort(java.util.ArrayList<Value[]> rows, int fromInclusive, int toExclusive)	Sort a list of rows using offset and limit.
static void	typeToString(java.lang.StringBuilder builder, int type)	Appends type information (DESC, NULLS FIRST, NULLS LAST) to the specified statement builder.

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, reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

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

session

private final SessionLocal session

queryColumnIndexes

private final int[] queryColumnIndexes

The column indexes of the order by expressions within the query.

sortTypes

private final int[] sortTypes

The sort type bit mask (DESCENDING, NULLS_FIRST, NULLS_LAST).

orderList

private final java.util.ArrayList<QueryOrderBy> orderList

The order list.

Constructor Detail

SortOrder

public SortOrder(SessionLocal session,
                 int[] queryColumnIndexes)

Construct a new sort order object with default sort directions.

Parameters:

session - the session

queryColumnIndexes - the column index list

SortOrder

public SortOrder(SessionLocal session,
                 int[] queryColumnIndexes,
                 int[] sortType,
                 java.util.ArrayList<QueryOrderBy> orderList)

Construct a new sort order object.

Parameters:

session - the session

queryColumnIndexes - the column index list

sortType - the sort order bit masks

orderList - the original query order list (if this is a query)

Method Detail

getSQL

public java.lang.StringBuilder getSQL(java.lang.StringBuilder builder,
                                      Expression[] list,
                                      int visible,
                                      int sqlFlags)

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

Parameters:

builder - string builder to append to

list - the expression list

visible - the number of columns in the select list

sqlFlags - formatting flags

Returns:

the specified string builder

typeToString

public static void typeToString(java.lang.StringBuilder builder,
                                int type)

Appends type information (DESC, NULLS FIRST, NULLS LAST) to the specified statement builder.

Parameters:

builder - string builder

type - sort type

compare

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

Compare two expression lists.

Specified by:

compare in interface java.util.Comparator<Value[]>

Parameters:

a - the first expression list

b - the second expression list

Returns:

the result of the comparison

sort

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

Sort a list of rows.

Parameters:

rows - the list of rows

sort

public void sort(java.util.ArrayList<Value[]> rows,
                 int fromInclusive,
                 int toExclusive)

Sort a list of rows using offset and limit.

Parameters:

rows - the list of rows

fromInclusive - the start index, inclusive

toExclusive - the end index, exclusive

getQueryColumnIndexes

public int[] getQueryColumnIndexes()

Get the column index list. This is the column indexes of the order by expressions within the query.

For the query "select name, id from test order by id, name" this is {1, 0} as the first order by expression (the column "id") is the second column of the query, and the second order by expression ("name") is the first column of the query.

Returns:

the list

getColumn

public Column getColumn(int index,
                        TableFilter filter)

Get the column for the given table filter, if the sort column is for this filter.

Parameters:

index - the column index (0, 1,..)

filter - the table filter

Returns:

the column, or null

getSortTypes

public int[] getSortTypes()

Get the sort order bit masks.

Returns:

the list

getOrderList

public java.util.ArrayList<QueryOrderBy> getOrderList()

Returns the original query order list.

Returns:

the original query order list

getSortTypesWithNullOrdering

public int[] getSortTypesWithNullOrdering()

Returns sort order bit masks with NULLS_FIRST or NULLS_LAST explicitly set.

Returns:

bit masks with either NULLS_FIRST or NULLS_LAST explicitly set.

addNullOrdering

public static int[] addNullOrdering(Database database,
                                    int[] sortTypes)

Add explicit NULLS_FIRST or NULLS_LAST where they aren't already specified.

Parameters:

database - the database

sortTypes - bit masks

Returns:

the specified array with possibly modified bit masks

getRowValueComparator

public java.util.Comparator<Value> getRowValueComparator()

Returns comparator for row values.

Returns:

comparator for row values.