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.field;
  
  import com.orm.androrm.DatabaseAdapter;
  import com.orm.androrm.DatabaseBuilder;
  import com.orm.androrm.Model;
  
  import android.content.Context;
  import android.database.SQLException;
  
  /**
   * This class is the superclass for all database fields,
   * that need a real field in the database. This for example 
   * is a {@link IntegerField} field, but not a {@link OneToManyField}. 
   * 
   * @author Philipp Giese
   *
   * @param <T>	The Java data type this field represents. 
   */
  public abstract class DataField<T> implements DatabaseField<T> {
  	
  	/**
  	 * Type descriptor of this field used for the 
  	 * database definition.
  	 */
  	protected String mType;
  	/**
  	 * Value of that field. 
  	 */
  	protected T mValue;
  	/**
  	 * Maximum length of that field.
  	 */
  	protected int mMaxLength;
  	
  	@Override
  	public T get() {
  		return mValue;
  	}
  	
  	@Override
  	public String getDefinition(String fieldName) {
  		String definition = "`" + fieldName + "` " + mType;
  		
  		if(mMaxLength > 0) {
  			definition += "(" + mMaxLength + ")";
  		}
  		
  		return definition;
  	}
  	
  	@Override
  	public void set(T value) {
  		mValue = value;
  	}
  	
  	@Override
  	public String toString() {
  		return String.valueOf(mValue);
  	}
  	
  	protected boolean exec(Context context, Class<? extends Model> model, String sql) {
  		DatabaseAdapter adapter = DatabaseAdapter.getInstance(context);
  		
  		adapter.open();
  		
  		try {
  			adapter.exec(sql);
  		} catch(SQLException e) {
  			adapter.close();
  		
  			return false;
  		}
  		
  		adapter.close();
  		return true;
  	}
  	
  	public boolean addToAs(Context context, Class<? extends Model> model, String name) {
  		String sql = "ALTER TABLE `" + DatabaseBuilder.getTableName(model) + "` "
  					+ "ADD COLUMN " + getDefinition(name);
  		
  		return exec(context, model, sql);
  				
  	}
  }
  