Android 使用数据库 SQlite

搞Android开发很久了，却还没有写过sqlite 先写写基础的，后面扩充。。。

packagecom.king.android.db;

importandroid.content.ContentValues;
importandroid.content.Context;
importandroid.database.Cursor;
importandroid.database.SQLException;
importandroid.database.sqlite.SQLiteDatabase;
importandroid.database.sqlite.SQLiteOpenHelper;

/**

*描述：数据库。。。
*作者：Andy.Liu
*时间：2012-8-2下午10:37:27
**/
publicclassMyDataBaseAdapter{

privatestaticfinalStringTAG="MyDataBaseAdapter";

privateContextmContext=null;

publicstaticfinalStringKEY_ID="_id";

publicstaticfinalStringKEY_NUM="num";

publicstaticfinalStringKEY_DATA="data";

privatestaticfinalStringDB_NAME="king.db";

privatestaticfinalStringTABLE_KING="king";

privatestaticfinalintDB_VERSION=1;

//创建表的语句
privatestaticfinalStringCREATE_TAB_KING=null;

//执行open()打开数据库，保存返回的数据库对象
privateSQLiteDatabasemSQlLiteDatabase=null;

//由SQLiteOpenHelper继承过来
privateDatabaseHelpermDatabaseHelper=null;

//继承SQLiteOpenHelper
privatestaticclassDatabaseHelperextendsSQLiteOpenHelper{

//构造函数创建数据库
publicDatabaseHelper(Contextcontext){
/**
*当调用getWriteableDatabase(),getReadableDatabase()方法时则创建一个数据库
*/
super(context,DB_NAME,null,DB_VERSION);

}

@Override/*创建数据表*/
publicvoidonCreate(SQLiteDatabasedb){
db.execSQL(CREATE_TAB_KING);
}

@Override//升级数据库
publicvoidonUpgrade(SQLiteDatabasedb,intoldVersion,intnewVersion){
db.execSQL("DROPTABLEIFEXISTSnotes");
onCreate(db);
}
}
//构造函数取得Context
publicMyDataBaseAdapter(Contextcontext){
this.mContext=context;
}

//打开数据库，返回数据库对象
publicvoidopen()throwsSQLException{
mDatabaseHelper=newDatabaseHelper(mContext);
mSQlLiteDatabase=mDatabaseHelper.getWritableDatabase();
}

//关闭数据库
publicvoidclose(){
mDatabaseHelper.close();
}

//插入一条数据
publiclonginsertData(intnum,Stringdata){
ContentValuesinitValues=newContentValues();
initValues.put(KEY_NUM,num);
initValues.put(KEY_DATA,data);
returnmSQlLiteDatabase.insert(TABLE_KING,KEY_ID,initValues);
}

//删除一条数据
publicbooleandeleteData(longrowId){
returnmSQlLiteDatabase.delete(TABLE_KING,KEY_ID+"="+rowId,null)>0;
}

//通过Cursor查询所有数据
publicCursorfetchAllData(){
returnmSQlLiteDatabase.query(TABLE_KING,newString[]{KEY_ID,KEY_NUM,KEY_DATA},null,null,null,null,null);
}

//查询指定数据
publicCursorfetchData(longrowId){
CursormCursor=mSQlLiteDatabase.query(true,TABLE_KING,newString[]{KEY_ID,KEY_NUM,KEY_DATA},KEY_ID+"="+rowId,null,null,null,null,null);
if(null!=mCursor){
mCursor.moveToFirst();
}
returnmCursor;
}

//更新一条数据
publicbooleanupdateData(longrowId,intnum,Stringdata){
ContentValuesargs=newContentValues();
args.put(KEY_NUM,num);
args.put(KEY_DATA,data);
returnmSQlLiteDatabase.update(TABLE_KING,args,KEY_ID+"="+rowId,null)>0;
}

}

更多相关文章

随机推荐