org.sqlproc.engine
Class SqlOrder

java.lang.Object
  org.sqlproc.engine.SqlOrder

public class SqlOrder
extends java.lang.Object

The list of ordering directives for the SQL Processor queries execution. The class layout is based on the Composite design pattern. Instances of this class can be obtained only using one of the factory methods.

For example there's a table PERSON with two columns - ID and NAME. The META SQL can be the next one:

 LIST_ALL_SQL= \
   select p.ID, p.NAME \
   from PERSON p \
   {#1 order by ID} \
   {#2 order by NAME}
 

In the case of SQL Processor invocation

 SqlEngine sqlEngine = sqlLoader.getSqlEngine("ALL");
 List<Person> list = sqlEngine.query(session, Person.class, null, SqlOrder.getAscOrder(1));
 

the output list is sorted in ascending order based on column ID.

In the case of SQL Processor invocation

 SqlEngine sqlEngine = sqlLoader.getSqlEngine("ALL");
 List<Person> list = sqlEngine.query(session, Person.class, new Object(), SqlOrder.getDescOrder(2));
 

the output list is sorted in descending order based on column NAME.

For more info please see the User's tutorial.

Author:

Vladimir Hudec

Nested Class Summary

static class

SqlOrder.Order The enumeration for the ordering directives.

Field Summary

private SqlOrder.Order	orderDirrection The ordering direction (no ordering, ascending or descending).
private int	orderId The ordering id.
private java.util.List<SqlOrder>	orders The list of all ordering rules.

Constructor Summary

private	SqlOrder() Creates a new empty ordering directives.
private	SqlOrder(int orderId, SqlOrder.Order orderDirrection) /** Creates a new ordering rule.

Method Summary

SqlOrder	addAscOrder(int orderId) Adds one more ascending ordering rule into the list of ordering directives.
SqlOrder	addDescOrder(int orderId) Adds one more descending ordering rule into the list of ordering directives.
SqlOrder	addOrder(int orderId) Adds one more ascending or descending ordering rule into the list of ordering directives.
static SqlOrder	getAscOrder(int orderId) The factory method.
static SqlOrder	getDescOrder(int orderId) The factory method.
static SqlOrder	getOrder() The factory method.
static SqlOrder	getOrder(int orderId) The factory method.
SqlOrder.Order	getOrderDirrection() Returns the ordering direction (no ordering, ascending or descending).
int	getOrderId() Returns the ordering id.
java.util.List<SqlOrder>	getOrders() Returns the list of ordering directives.

Methods inherited from class java.lang.Object

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

Field Detail

orderId

private int orderId

The ordering id. This value should correspond to the order number in META SQL {#NNN order by ...}.

orderDirrection

private SqlOrder.Order orderDirrection

The ordering direction (no ordering, ascending or descending).

orders

private java.util.List<SqlOrder> orders

The list of all ordering rules.

Constructor Detail

SqlOrder

private SqlOrder()

Creates a new empty ordering directives. This constructor is a private one to prevent an instantiation without factory methods.

SqlOrder

private SqlOrder(int orderId,
                 SqlOrder.Order orderDirrection)

/** Creates a new ordering rule. This constructor is a private one to prevent an instantiation without factory methods.

Parameters:

orderId - the ordering id

orderDirrection - the ordering direction

Method Detail

getOrder

public static SqlOrder getOrder()

The factory method.

Returns:

the empty ordering directive list

getAscOrder

public static SqlOrder getAscOrder(int orderId)

The factory method.

Parameters:

orderId - the ordering id

Returns:

the ordering directive list with one ascending ordering rule

getDescOrder

public static SqlOrder getDescOrder(int orderId)

The factory method.

Parameters:

orderId - the ordering id

Returns:

the ordering directive list with one descending ordering rule

getOrder

public static SqlOrder getOrder(int orderId)

The factory method.

Parameters:

orderId - the ordering id. Can be a negative one for a descending ordering rule.

Returns:

the ordering directive list with one ascending or descending ordering rule

addAscOrder

public SqlOrder addAscOrder(int orderId)

Adds one more ascending ordering rule into the list of ordering directives.

Parameters:

orderId - the ordering id

Returns:

the updated ordering directive list

addDescOrder

public SqlOrder addDescOrder(int orderId)

Adds one more descending ordering rule into the list of ordering directives.

Parameters:

orderId - the ordering id

Returns:

the updated ordering directive list

addOrder

public SqlOrder addOrder(int orderId)

Adds one more ascending or descending ordering rule into the list of ordering directives.

Parameters:

orderId - the ordering id. Can be a negative one for a descending ordering rule.

Returns:

the updated ordering directive list

getOrderId

public int getOrderId()

Returns the ordering id. This value should correspond to the order number in META SQL {#NNN order by ...}.

Returns:

the ordering id

getOrderDirrection

public SqlOrder.Order getOrderDirrection()

Returns the ordering direction (no ordering, ascending or descending).

Returns:

the ordering direction

getOrders

public java.util.List<SqlOrder> getOrders()

Returns the list of ordering directives.

Returns:

the list of ordering directives