TurtleDB
A mini distributed database system
src/ca/uqac/dim/turtledb/TableLinkVisitor.java
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00001 /*-------------------------------------------------------------------------
00002     Simple distributed database engine
00003     Copyright (C) 2012  Sylvain Hallé
00004 
00005     This program is free software: you can redistribute it and/or modify
00006     it under the terms of the GNU General Public License as published by
00007     the Free Software Foundation, either version 3 of the License, or
00008     (at your option) any later version.
00009 
00010     This program is distributed in the hope that it will be useful,
00011     but WITHOUT ANY WARRANTY; without even the implied warranty of
00012     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00013     GNU General Public License for more details.
00014 
00015     You should have received a copy of the GNU General Public License
00016     along with this program.  If not, see <http://www.gnu.org/licenses/>.
00017  -------------------------------------------------------------------------*/
00018 package ca.uqac.dim.turtledb;
00019 
00020 import java.util.*;
00021 
00022 public class TableLinkVisitor extends EmptyQueryVisitor
00023 {
00024   protected Map<String,Relation> m_tables;
00025   
00026   public TableLinkVisitor(VariableTable table)
00027   {
00028     m_tables = new HashMap<String,Relation>();
00029     m_tables.put(table.getName(), table);
00030   }
00031   
00032   public TableLinkVisitor(Map<String,Relation> tables)
00033   {
00034     m_tables = tables;
00035   }
00036   
00037   public void visit(VariableTable t) //throws EmptyQueryVisitor.VisitorException
00038   {
00039     String table_name = t.getName();
00040     Relation r = m_tables.get(table_name);
00041     /*if (r == null)
00042       throw new EmptyQueryVisitor.VisitorException("Table " + table_name + " cannot be found");*/
00043     if (r != null)
00044       t.setRelation(r);
00045   }
00046 }