数据库操作总结

SQLiteDatabase 是关于数据库操作的 可用于 insert delete update query 等操作 可惜美中不足的是：

1. 不支持创建数据库

2. 不支持版本更新

所以出现了SQLiteOpenHelper类，是一个抽象类，一般继承它

一般里面要写3个函数：

构造函数

oncreate（）初始化的时候使用，一般用于建表

onupdate（）升级时候使用，一般删除现有表，然后在重建

然后使用SQLiteOpenHelper的类函数：getWritableDatabase（）或者getReadableDatabase（）获取数据库实例

然后进行query，insert，update，delete操作。

 mDb.insert(TABLE_NAME, null, newValues);

newValues是一个类似bundle和hashtable的集合，存储键值对

mDb.delete(TABLE_NAME, ID + "=" + id, null);

return mDb.delete(TABLE_NAME, null, null);

public PersonInfo[] queryOneData(long id)

 {

  Cursor result = mDb.query(TABLE_NAME, new String[] { ID,
    PERSONINFO_CODE, PERSONINFO_DISPLAYPICTURE,
    PERSONINFO_NICKNAME, PERSONINFO_BIRTHDAY, PERSONINFO_GENDER,
    PERSONINFO_SIGNATURE, PERSONINFO_SIGNATUREDATETIME,
    PERSONINFO_PASSWORD, PERSONINFO_DISPLAYPICTUREBINARY,
    PERSONINFO_REGISTERTIME, PERSONINFO_UPDATETIME },

  ID + "=" + id, null, null, null, null);

  PersonInfo[]pInfo=ConvertToPersonInfo(result);
  if(result!=null&&!result.isClosed()){
   result.close();
   result=null;
  }
  return pInfo;

 }

 

public long updateOneData(long id, PersonInfo personInfo)

 {

  ContentValues newValues = new ContentValues();

  newValues.put(PERSONINFO_CODE, personInfo.getCode());

  newValues
    .put(PERSONINFO_DISPLAYPICTURE, personInfo.getDisplayPicture());

  newValues.put(PERSONINFO_NICKNAME, personInfo.getNickname());

  newValues.put(PERSONINFO_BIRTHDAY, personInfo.getBirthday());

  newValues.put(PERSONINFO_GENDER, personInfo.getGender());

  newValues.put(PERSONINFO_SIGNATURE, personInfo.getSignature());

  newValues.put(PERSONINFO_SIGNATUREDATETIME, personInfo
    .getSignatureDatatime());

  newValues.put(PERSONINFO_PASSWORD, personInfo.getPassword());

  newValues.put(PERSONINFO_DISPLAYPICTUREBINARY, "");

  newValues.put(PERSONINFO_REGISTERTIME, personInfo.getRegisterTime());

  newValues.put(PERSONINFO_UPDATETIME, personInfo.getUpdateTime());

  return mDb.update(TABLE_NAME, newValues, ID + "=" + id, null);

 }

 

public long insert(PersonInfo personInfo)

 {

  ContentValues newValues = new ContentValues();

  newValues.put(PERSONINFO_CODE, personInfo.getCode());

  newValues
    .put(PERSONINFO_DISPLAYPICTURE, personInfo.getDisplayPicture());

  newValues.put(PERSONINFO_NICKNAME, personInfo.getNickname());

  newValues.put(PERSONINFO_BIRTHDAY, personInfo.getBirthday());

  newValues.put(PERSONINFO_GENDER, personInfo.getGender());

  newValues.put(PERSONINFO_SIGNATURE, personInfo.getSignature());

  newValues.put(PERSONINFO_SIGNATUREDATETIME, personInfo
    .getSignatureDatatime());

  newValues.put(PERSONINFO_PASSWORD, personInfo.getPassword());

  newValues.put(PERSONINFO_DISPLAYPICTUREBINARY, "");

  newValues.put(PERSONINFO_REGISTERTIME, personInfo.getRegisterTime());

  newValues.put(PERSONINFO_UPDATETIME, personInfo.getUpdateTime());

  return mDb.insert(TABLE_NAME, null, newValues);

 }

public long deleteOneData(long id)

 {

  return mDb.delete(TABLE_NAME, ID + "=" + id, null);

 }