SQLiteHelper

 /**
  * 实现对表的创建、更新、变更列名操作
  *
  *
  */
 public class SQLiteHelper extends SQLiteOpenHelper {
     public static final String DB_NAME = "historyDB";
     public static final String TB_NAME = "historyTB";
 
     public SQLiteHelper(Context context)
     {
         super(context, DB_NAME, null, 1);
     }
 
     /**
      * 创建新表
      */
     @Override
     public void onCreate(SQLiteDatabase db) {
         db.execSQL("CREATE TABLE IF NOT EXISTS " +
                 TB_NAME + "(" +
                 //HistoryBean.ID + " integer primary key," +
                 HistoryBean.URL + " varchar," +
                 HistoryBean.TIME + " integer,"+
                 HistoryBean.NAME + " varchar"+
                 ")");
     }
 
     /**
      * 当检测与前一次创建数据库版本不一样时，先删除表再创建新表
      */
     @Override
     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
         db.execSQL("DROP TABLE IF EXISTS " + TB_NAME);
         onCreate(db);
     }
 
     /**
      * 变更列名
      * @param db
      * @param oldColumn
      * @param newColumn
      * @param typeColumn
      */
     public void updateColumn(SQLiteDatabase db, String oldColumn, String newColumn, String typeColumn){
         try{
             db.execSQL("ALTER TABLE " +
                     TB_NAME + " CHANGE " +
                     oldColumn + " "+ newColumn +
                     " " + typeColumn
             );
         }catch(Exception e){
             e.printStackTrace();
         }
     }
 
 }