super(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) 

onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) 

package cc.database; 
 
import android.content.Context; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteDatabase.CursorFactory; 
import android.database.sqlite.SQLiteOpenHelper; 
/** 
 * Demo描述: 
 * SQLite数据库版本升级的管理实现 
 * 
 * 参考资料: 
 * http://blog.csdn.net/guolin_blog 
 * Thank you very much 
 */ 
public class DataBaseOpenHelper extends SQLiteOpenHelper { 
  private final static String DATABASE_NAME="test.db"; 
  private static DataBaseOpenHelper mDataBaseOpenHelper; 
   
  public static final String CREATE_PERSON= 
  "create table person(personid integer primary key autoincrement,name varchar(20),phone VARCHAR(12))"; 
   
  public DataBaseOpenHelper(Context context,String name,CursorFactory factory,int version) { 
    super(context, name, factory, version); 
  } 
 
   
  //注意: 
  //将DataBaseOpenHelper写成单例的. 
  //否则当在一个for循环中频繁调用openHelper.getWritableDatabase()时 
  //会报错,提示数据库没有执行关闭操作 
  static synchronized DataBaseOpenHelper getDBInstance(Context context) { 
    if (mDataBaseOpenHelper == null) { 
      mDataBaseOpenHelper = new DataBaseOpenHelper(context,DATABASE_NAME,null,1); 
    } 
    return mDataBaseOpenHelper; 
  }  
   
  @Override 
  public void onCreate(SQLiteDatabase db) { 
    db.execSQL(CREATE_PERSON); 
  } 
 
  @Override 
  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     
  } 
 
} 

package cc.database; 
 
import android.content.Context; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteDatabase.CursorFactory; 
import android.database.sqlite.SQLiteOpenHelper; 
 
public class DataBaseOpenHelper extends SQLiteOpenHelper { 
  private final static String DATABASE_NAME="test.db"; 
  private static DataBaseOpenHelper mDataBaseOpenHelper; 
   
  public static final String CREATE_PERSON= 
  "create table person(personid integer primary key autoincrement,name varchar(20),phone VARCHAR(12))"; 
   
  public static final String CREATE_STUDENT= 
  "create table student(studentid integer primary key autoincrement,name varchar(20),phone VARCHAR(12))"; 
   
  public DataBaseOpenHelper(Context context,String name,CursorFactory factory,int version) { 
    super(context, name, factory, version); 
  } 
 
   
  //注意: 
  //将DataBaseOpenHelper写成单例的. 
  //否则当在一个for循环中频繁调用openHelper.getWritableDatabase()时 
  //会报错,提示数据库没有执行关闭操作 
  static synchronized DataBaseOpenHelper getDBInstance(Context context) { 
    if (mDataBaseOpenHelper == null) { 
      //改动1 
      mDataBaseOpenHelper = new DataBaseOpenHelper(context,DATABASE_NAME,null,2); 
    } 
    return mDataBaseOpenHelper; 
  }  
   
  @Override 
  public void onCreate(SQLiteDatabase db) { 
    db.execSQL(CREATE_PERSON); 
    //改动2 
    db.execSQL(CREATE_STUDENT); 
  } 
 
  @Override 
  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
    //改动3 
    switch (oldVersion) { 
     
    case 1: 
    db.execSQL(CREATE_STUDENT); 
 
    default: 
    } 
  } 
 
} 

package cc.database; 
 
import android.content.Context; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteDatabase.CursorFactory; 
import android.database.sqlite.SQLiteOpenHelper; 
 
public class DataBaseOpenHelper extends SQLiteOpenHelper { 
  private final static String DATABASE_NAME="test.db"; 
  private static DataBaseOpenHelper mDataBaseOpenHelper; 
   
  //改动1 
  public static final String CREATE_PERSON= 
  "create table person(personid integer primary key autoincrement,name varchar(20),phone VARCHAR(12)),genderid integer)"; 
   
  public static final String ALTER_PERSON="alter table person add column genderid integer"; 
   
  public static final String CREATE_STUDENT= 
  "create table student(studentid integer primary key autoincrement,name varchar(20),phone VARCHAR(12))"; 
   
  public DataBaseOpenHelper(Context context,String name,CursorFactory factory,int version) { 
    super(context, name, factory, version); 
  } 
 
   
  //注意: 
  //将DataBaseOpenHelper写成单例的. 
  //否则当在一个for循环中频繁调用openHelper.getWritableDatabase()时 
  //会报错,提示数据库没有执行关闭操作 
  static synchronized DataBaseOpenHelper getDBInstance(Context context) { 
    if (mDataBaseOpenHelper == null) { 
      //改动2 
      mDataBaseOpenHelper = new DataBaseOpenHelper(context,DATABASE_NAME,null,3); 
    } 
    return mDataBaseOpenHelper; 
  }  
   
  @Override 
  public void onCreate(SQLiteDatabase db) { 
    db.execSQL(CREATE_PERSON); 
    db.execSQL(CREATE_STUDENT); 
  } 
 
  @Override 
  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
    switch (oldVersion) { 
     
    case 1: 
    db.execSQL(CREATE_STUDENT); 
     
    //改动3 
    case 2: 
    db.execSQL(ALTER_PERSON); 
 
    default: 
    } 
  } 
 
}