Android如何导入已有的外部数据库（在raw下自己导入db文件）

*** 作方法是用FileInputStream读取原数据库，再用 FileOutputStream把读取到的东西写入到那个目录。 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 packagecom.android.ImportDatabaseimportjava.io.Fileimportjava.io.FileNotFoundExceptionimportjava.io.FileOutputStreamimportjava.io.IOExceptionimportjava.io.InputStreamimportandroid.content.Contextimportandroid.database.sqlite.SQLiteDatabaseimportandroid.os.Environmentimportandroid.util.LogpublicclassDBManager { privatefinalintBUFFER_SIZE =400000publicstaticfinalString DB_NAME ="countries.db"//保存的数据库文件名 publicstaticfinalString PACKAGE_NAME ="com.android.ImportDatabase"publicstaticfinalString DB_PATH ="/data" + Environment.getDataDirectory().getAbsolutePath() +"/" + PACKAGE_NAME//在手机里存放数据库的位置 privateSQLiteDatabase databaseprivateContext contextDBManager(Context context) { this.context = context} publicvoidopenDatabase() { this.database =this.openDatabase(DB_PATH +"/"+ DB_NAME)} privateSQLiteDatabase openDatabase(String dbfile) { try{ if(!(newFile(dbfile).exists())) { //判断数据库文件是否存在，若不存在则执行导入，否则直接打开数据库 InputStream is =this.context.getResources().openRawResource( R.raw.countries)//欲导入的数据库 FileOutputStream fos =newFileOutputStream(dbfile)byte[] buffer =newbyte[BUFFER_SIZE]intcount =0while((count = is.read(buffer)) >0) { fos.write(buffer,0, count)} fos.close()is.close()} SQLiteDatabase db = SQLiteDatabase.openOrCreateDatabase(dbfile, null)returndb}catch(FileNotFoundException e) { Log.e("Database","File not found")e.printStackTrace()}catch(IOException e) { Log.e("Database","IO exception")e.printStackTrace()} returnnull} ? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 packagecom.android.ImportDatabaseimportjava.util.ArrayListimportandroid.app.Activityimportandroid.database.Cursorimportandroid.database.sqlite.SQLiteDatabaseimportandroid.os.BundlepublicclassTaxiActivityextendsActivity { privateSQLiteDatabase databaseArrayList CITY@Override publicvoidonCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState)setContentView(R.layout.main)database = SQLiteDatabase.openOrCreateDatabase(DBManager.DB_PATH +"/"+ DBManager.DB_NAME,null)CITY = getCity()// do something with CITY database.close()} privateArrayList getCity() { Cursor cur = database.rawQuery("SELECT city.id_city, city.name FROM taxi, city WHERE city.id_city = taxi.id_city GROUP BY city.id_city",null)if(cur !=null) { intNUM_CITY = cur.getCount()ArrayList taxicity =newArrayList(NUM_CITY)if(cur.moveToFirst()) { do{ String name = cur.getString(cur.getColumnIndex("name"))intid = cur.getInt(cur.getColumnIndex("id_city"))CityClass city =newCityClass("",0)System.out.println(name)//额外添加一句，把select到的信息输出到Logcat city.city_name = namecity.city_id = idtaxicity.add(city)}while(cur.moveToNext())} returntaxicity}else{ returnnull} } } 查看输出的结果：

导入已有的外部数据库的方法：

第一种是右击数据库，然后点击附加。出现下面的界面。然后选择添加，添加上你要添加的mdf文件即可。

第二种方法是：新建查询，然后输入下列语句，

EXEC sp_attach_db @dbname = 'yourdatabasename',

@filename1 = 'x:\路径\MSSQL\Data\pubs.mdf',

@filename2 = 'x:\路径\MSSQL\Data.Ldf

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