net.sf.basedb.core.query
Class SubqueryExpression

java.lang.Object
  net.sf.basedb.core.query.SubqueryExpression

All Implemented Interfaces:

Expression, QueryElement

public class SubqueryExpression
extends Object
implements Expression

Expression that returns the result of a query as it's value. This expression is used with subqueries.

Version:

2.9

Author:

Nicklas

See Also:

Expressions.any(Query), Expressions.all(Query)

Last modified

$Date: 2010-04-21 11:48:29 +0200 (Wed, 21 Apr 2010) $

Field Summary

private String	operator
private Query	subquery

Constructor Summary

SubqueryExpression(String operator, Query subquery)

Method Summary

boolean	equals(Object other) This expression is equal to another SubqueryExpression if they use the same operator and reference the same subquery instance.
Collection<? extends QueryElement>	getChildren() Get the children of this query element or null if it has no children.
int	hashCode()
String	toQl(Query query, DbControl dc) Create a query language string of the query element.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

operator

private final String operator

subquery

private final Query subquery

Constructor Detail

SubqueryExpression

SubqueryExpression(String operator,
                   Query subquery)

Method Detail

toQl

public String toQl(Query query,
                   DbControl dc)
            throws BaseException

Description copied from interface: QueryElement

Create a query language string of the query element. Use the Query.getQueryType() method to find out which query language is wanted in case the element requires different syntax for different languages.

Specified by:

toQl in interface QueryElement

Parameters:

query - The query that is about to be executed

dc - The DbControl object used to execute the query

Throws:

BaseException - If there is any other error

getChildren

public Collection<? extends QueryElement> getChildren()

Description copied from interface: QueryElement

Get the children of this query element or null if it has no children. For example the AddExpression has two children, the expression beeing added.

Specified by:

getChildren in interface QueryElement

Returns:

Always null

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object other)

This expression is equal to another SubqueryExpression if they use the same operator and reference the same subquery instance.

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object