org.apache.openjpa.jdbc.sql.Joins Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
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package org.apache.openjpa.jdbc.sql;
import org.apache.openjpa.jdbc.meta.ClassMapping;
import org.apache.openjpa.jdbc.schema.ForeignKey;
import org.apache.openjpa.jdbc.schema.Table;
import org.apache.openjpa.kernel.exps.Context;
/**
* Tracks joins made when traversing relations in a select.
*
* @author Abe White
*/
public interface Joins {
/**
* Whether we have any joins.
*/
public boolean isEmpty();
/**
* Whether this joins path results in outer joins.
*/
public boolean isOuter();
/**
* Perform a cross join on the given tables.
*/
public Joins crossJoin(Table localTable, Table foreignTable);
/**
* Join the columns of the given foreign key.
*/
public Joins join(ForeignKey fk, boolean inverse, boolean toMany);
/**
* Join the columns of the given foreign key.
*/
public Joins outerJoin(ForeignKey fk, boolean inverse, boolean toMany);
/**
* Join the columns of the given foreign key, which represents a relation
* via the given field name.
*/
public Joins joinRelation(String name, ForeignKey fk, ClassMapping target,
int subclasses, boolean inverse, boolean toMany);
/**
* Join the columns of the given foreign key, which represents a relation
* via the given field name.
*/
public Joins outerJoinRelation(String name, ForeignKey fk,
ClassMapping target, int subclasses, boolean inverse, boolean toMany);
/**
* Set the variable name being traversed into with the next join.
*/
public Joins setVariable(String var);
/**
* Set the subquery alias.
*/
public Joins setSubselect(String alias);
/**
* Set subquery context when traversing into the next join is
* in transition from parent context to subquery.
* @param context
*/
public Joins setJoinContext(Context context);
/**
* Set the correlated variable name being traversed into
* with the next join.
*/
public Joins setCorrelatedVariable(String var);
/**
* Return correlated variable name
* @return
*/
public String getCorrelatedVariable();
/**
* Move joins that belong to subquery's parent
*/
public void moveJoinsToParent();
}