mdb
3a283a16e1
git-svn-id: https://samskivert.googlecode.com/svn/trunk@2355 6335cc39-0255-0410-8fd6-9bcaacd3b74c
104 lines
3.1 KiB
Java
104 lines
3.1 KiB
Java
//
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// $Id$
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//
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// samskivert library - useful routines for java programs
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// Copyright (C) 2006-2007 Michael Bayne, Pär Winzell
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//
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// This library is free software; you can redistribute it and/or modify it
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// under the terms of the GNU Lesser General Public License as published
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// by the Free Software Foundation; either version 2.1 of the License, or
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// (at your option) any later version.
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//
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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// Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public
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// License along with this library; if not, write to the Free Software
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// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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package com.samskivert.jdbc.depot.clause;
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import java.util.Collection;
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import com.samskivert.jdbc.depot.PersistentRecord;
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import com.samskivert.jdbc.depot.expression.ColumnExp;
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import com.samskivert.jdbc.depot.expression.ExpressionVisitor;
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import com.samskivert.jdbc.depot.expression.SQLExpression;
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import com.samskivert.jdbc.depot.operator.Conditionals.Equals;
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/**
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* Represents a JOIN.
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*/
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public class Join extends QueryClause
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{
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/** Indicates the join type to be used. The default is INNER. */
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public static enum Type { INNER, LEFT_OUTER, RIGHT_OUTER };
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public Join (Class<? extends PersistentRecord> pClass, String pCol,
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Class<? extends PersistentRecord> joinClass, String jCol)
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{
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_joinClass = joinClass;
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_joinCondition = new Equals(new ColumnExp(joinClass, jCol), new ColumnExp(pClass, pCol));
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}
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public Join (ColumnExp primary, ColumnExp join)
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{
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_joinClass = join.getPersistentClass();
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_joinCondition = new Equals(primary, join);
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}
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public Join (Class<? extends PersistentRecord> joinClass, SQLExpression joinCondition)
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{
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_joinClass = joinClass;
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_joinCondition = joinCondition;
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}
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/**
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* Configures the type of join to be performed.
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*/
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public Join setType (Type type)
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{
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_type = type;
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return this;
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}
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public Type getType ()
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{
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return _type;
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}
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public Class<? extends PersistentRecord> getJoinClass ()
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{
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return _joinClass;
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}
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public SQLExpression getJoinCondition ()
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{
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return _joinCondition;
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}
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// from SQLExpression
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public void accept (ExpressionVisitor builder) throws Exception
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{
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builder.visit(this);
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}
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// from SQLExpression
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public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
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{
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classSet.add(_joinClass);
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_joinCondition.addClasses(classSet);
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}
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/** Indicates the type of join to be performed. */
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protected Type _type = Type.INNER;
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/** The class of the table we're to join against. */
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protected Class<? extends PersistentRecord> _joinClass;
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/** The condition used to join in the new table. */
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protected SQLExpression _joinCondition;
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}
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