Package com.arcadedb.query.sql.parser

Class SubQueryCollector

java.lang.Object

com.arcadedb.query.sql.parser.SubQueryCollector

public class SubQueryCollector
extends Object

This class is used by the query planner to extract subqueries and move them to LET clause
An example:

select from foo where name in (select name from bar)

will become

select from foo<br> let _$$$SUBQUERY$$_0 = (select name from bar)<br> where name in _$$$SUBQUERY$$_0

Author:

Luigi Dell'Aquila (luigi.dellaquila-(at)-gmail.com)

Field Summary

Fields

Modifier and Type	Field	Description
protected static String	GENERATED_ALIAS_PREFIX
protected int	nextAliasId
protected Map<Identifier,Statement>	subQueries

Constructor Summary

Constructors

Constructor	Description
SubQueryCollector()

Method Summary

Modifier and Type	Method	Description
Identifier	addStatement(Identifier alias, Statement stm)
Identifier	addStatement(Statement stm)
protected Identifier	getNextAlias()
Map<Identifier,Statement>	getSubQueries()
void	reset()	clean the content, but NOT the counter!

Methods inherited from class java.lang.Object

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

Field Detail

GENERATED_ALIAS_PREFIX

protected static final String GENERATED_ALIAS_PREFIX

See Also:

Constant Field Values

nextAliasId

protected int nextAliasId

subQueries

protected Map<Identifier,Statement> subQueries

Constructor Detail

SubQueryCollector

public SubQueryCollector()

Method Detail

getNextAlias

protected Identifier getNextAlias()

reset

public void reset()

clean the content, but NOT the counter!

addStatement

public Identifier addStatement(Identifier alias,
                               Statement stm)

addStatement

public Identifier addStatement(Statement stm)

getSubQueries

public Map<Identifier,Statement> getSubQueries()