我正在開發(fā)一個(gè)包含 100 個(gè)元素的數(shù)據(jù)庫(kù)的小型應(yīng)用程序。我導(dǎo)入了數(shù)據(jù)庫(kù)，但只有一個(gè)模擬器（我擁有的 3 個(gè)女巫）運(yùn)行正常。我發(fā)現(xiàn)它運(yùn)行沒有問題，因?yàn)椤癝ongs.db”數(shù)據(jù)庫(kù)存在于 data/data/myapppackage/databases/ 文件夾中，如果不對(duì)設(shè)備進(jìn)行 root，我將無(wú)法訪問。我通過互聯(lián)網(wǎng)搜索解決此問題的不同方法和解決方案，但沒有任何效果。我是 android 編程的新手，對(duì)于這種問題，沒有任何教程。public class DatabaseHelper extends SQLiteOpenHelper { public static final String DATABASE_NAME = "Songs.db"; public static final String TABLE_NAME = "songs_table"; public static final String COL_1 = "ID"; public static final String COL_2 = "TITLE"; public DatabaseHelper (Context context) { super( context, DATABASE_NAME, null, 1 ); SQLiteDatabase db = this.getWritableDatabase(); } public Cursor getData(int id) { SQLiteDatabase db = this.getReadableDatabase(); Cursor res = db.rawQuery( "select TITLE from songs_table where ID="+id+"", null ); return res; }}和 PlayerTurn 類myDb = new DatabaseHelper( this );Cursor rs = db.getData( b );rs.moveToFirst();tit = rs.getString( rs.getColumnIndex( db.COL_2 ) );我大多數(shù)時(shí)候收到的錯(cuò)誤消息是android.database.sqlite.SQLiteException: no such table: songs_table (code 1): 誰(shuí)能幫幫我？我花了將近 15 個(gè)小時(shí)...
1 回答
拉莫斯之舞
TA貢獻(xiàn)1820條經(jīng)驗(yàn) 獲得超10個(gè)贊
您可以將數(shù)據(jù)庫(kù)復(fù)制到 SD 卡中，您可以隨時(shí)從 SD 卡訪問數(shù)據(jù)庫(kù)
試試這個(gè)代碼：
try {
File sd = Environment.getExternalStorageDirectory();
File data = Environment.getDataDirectory();
if (sd.canWrite()) {
String currentDBPath = "data/"+sPackageName+"/databases/"+sDBName;
String backupDBPath = "/.appname-external-data-cache/"+sDBName; //"{database name}";
File dir = new File(sd,backupDBPath.replace(sDBName,""));
if(dir.mkdir()) {
}
File currentDB = new File(data, currentDBPath);
File backupDB = new File(sd, backupDBPath);
if (currentDB.exists()) {
FileChannel src = new FileInputStream(currentDB).getChannel();
FileChannel dst = new FileOutputStream(backupDB).getChannel();
dst.transferFrom(src, 0, src.size());
src.close();
dst.close();
}
}
} catch (Exception e) {
}
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