content: /**
   * 	Copyright (c) 2010 Philipp Giese
   * 
   * Permission is hereby granted, free of charge, to any person obtaining
   * a copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sublicense, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   * 
   * The above copyright notice and this permission notice shall be
   * included in all copies or substantial portions of the Software.
   * 
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
   * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
   * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
   * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   */
  package com.orm.androrm.statement;
  
  /**
   * This class is the abstract representation of a JOIN
   * statement. 
   * 
   * @author Philipp Giese
   */
  public class JoinStatement {
  	
  	private SelectStatement mLeft;
  	private SelectStatement mRight;
  	private String mLeftAlias;
  	private String mRightAlias;
  	private String mLeftColumn;
  	private String mRightColumn;
  
  	private String buildStatement() {
  		String join = "(" +
  				mLeft.toString() + 
  			") AS " + mLeftAlias + 
  			" JOIN (" +
  				mRight.toString() +
  			") AS " + mRightAlias +
  			" ON " + 
  				mLeftAlias + "." + mLeftColumn + 
  				"=" +
  				mRightAlias + "." + mRightColumn;
  		
  		return join;
  				
  	}
  	
  	/**
  	 * Creates the left side of the join from a subselect and 
  	 * masks it with the given alias. 
  	 * 
  	 * @param left	Left side of the join as {@link SelectStatement subselect}. 
  	 * @param as	Alias for the left side. 
  	 * 
  	 * @return	<code>this</code> for chaining.
  	 */
  	public JoinStatement left(SelectStatement left, String as) {
  		mLeft = left;
  		mLeftAlias = as;
  		
  		return this;
  	}
  	
  	/**
  	 * Sets the given table as the left side of the join and
  	 * masks it with the given alias. 
  	 * 
  	 * @param tableName	Table name.
  	 * @param as		Alias.
  	 * 
  	 * @return <code>this</code> for chaining.
  	 */
  	public JoinStatement left(String tableName, String as) {
  		SelectStatement select = new SelectStatement();
  		select.from(tableName);
  		
  		return left(select, as);
  	}
  	
  	/**
  	 * Defines on which columns this join should happen. 
  	 * 
  	 * @param leftColum		Name of the column in the left table.
  	 * @param rightColumn	Name of the column in the right table.
  	 * 
  	 * @return <code>this</code> for chaining.
  	 */
  	public JoinStatement on(String leftColum, String rightColumn) {
  		mLeftColumn = leftColum;
  		mRightColumn = rightColumn;
  		
  		return this;
  	}
  	
  	/**
  	 * Creates the right side of the join from a subselect and 
  	 * masks it with the given alias. 
  	 * 
  	 * @param right	Right side of the join as {@link SelectStatement subselect}. 
  	 * @param as	Alias for the right side. 
  	 * 
  	 * @return	<code>this</code> for chaining.
  	 */
  	public JoinStatement right(SelectStatement right, String as) {
  		mRight = right;
  		mRightAlias = as;
  		
  		return this;
  	}
  	
  	/**
  	 * Sets the given table as the right side of the join and
  	 * masks it with the given alias. 
  	 * 
  	 * @param tableName	Table name.
  	 * @param as		Alias.
  	 * 
  	 * @return <code>this</code> for chaining.
  	 */
  	public JoinStatement right(String tableName, String as) {
  		SelectStatement select = new SelectStatement();
  		select.from(tableName);
  		
  		return right(select, as);
  	}
  	
  	@Override
  	public String toString() {
  		return buildStatement();
  	}
  }
  