我正在使用this tutorial将数据库导入我的应用程序。
它在API 10上运行良好，
但是在API 17上会抛出以下错误：
05-19 14:52:46.492: E/SQLiteLog(1893): (14) cannot open file at line 30176 of [00bb9c9ce4]
05-19 14:52:46.492: E/SQLiteLog(1893): (14) os_unix.c:30176: (2) open(/data/data/com.example.koday/databases/dizionario7.sqlite) -
05-19 14:52:46.492: E/SQLiteDatabase(1893): Failed to open database '/data/data/com.example.koday/databases/dizionario7.sqlite'.
05-19 14:52:46.492: E/SQLiteDatabase(1893): android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:209)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:193)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:463)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:185)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:177)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:804)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:789)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:694)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:669)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at com.example.koday.DataBaseHelper.checkDataBase(DataBaseHelper.java:82)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at com.example.koday.DataBaseHelper.createDataBase(DataBaseHelper.java:45)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at com.example.koday.MainActivity.frontquiz(MainActivity.java:70)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at com.example.koday.MainActivity.onCreate(MainActivity.java:64)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.app.Activity.performCreate(Activity.java:5104)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.app.ActivityThread.access$600(ActivityThread.java:141)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.os.Handler.dispatchMessage(Handler.java:99)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.os.Looper.loop(Looper.java:137)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at android.app.ActivityThread.main(ActivityThread.java:5039)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at java.lang.reflect.Method.invokeNative(Native Method)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at java.lang.reflect.Method.invoke(Method.java:511)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
05-19 14:52:46.492: E/SQLiteDatabase(1893): at dalvik.system.NativeStart.main(Native Method)
05-19 14:52:47.683: E/(1893): database aperto
05-19 14:52:47.683: E/SQLiteLog(1893): (1) no such table: dati
这是我的代码：
public class DataBaseHelper extends SQLiteOpenHelper {
// The Android's default system path of your application database.
private static String DB_PATH = "/data/data/com.example.koday/databases/";
private static String DB_NAME = "dizionario7.sqlite";
private SQLiteDatabase myDataBase;
private final Context myContext;
/**
* Constructor Takes and keeps a reference of the passed context in order to
* access to the application assets and resources.
*
* @param context
*/
public DataBaseHelper(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
}
/**
* Creates a empty database on the system and rewrites it with your own
* database.
* */
public void createDataBase() throws IOException {
boolean dbExist = checkDataBase();
if (dbExist) {
// do nothing - database already exist
} else {
// By calling this method and empty database will be created into
// the default system path
// of your application so we are gonna be able to overwrite that
// database with our database.
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
/**
* Check if the database already exist to avoid re-copying the file each
* time you open the application.
*
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase() {
SQLiteDatabase checkDB = null;
try {
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
} catch (SQLiteException e) {
// database does't exist yet.
}
if (checkDB != null) {
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies your database from your local assets-folder to the just created
* empty database in the system folder, from where it can be accessed and
* handled. This is done by transfering bytestream.
* */
private void copyDataBase() throws IOException {
// Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
// Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
// transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
// Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException {
// Open the database
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
}
@Override
public synchronized void close() {
if (myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
// Add your public helper methods to access and get content from the
// database.
// You could return cursors by doing "return myDataBase.query(....)" so it'd
// be easy
// to you to create adapters for your views.
// Getting single contact
String getkword(String word) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query("data",
new String[] { "_id", "english", "korean" }, "english" + "=?",
new String[] { word }, null, null, null, null);
if (cursor != null)
cursor.moveToFirst();
String kword = cursor.getString(2);
// return contact
db.close();
return kword;
}
// Getting All Contacts
public Cursor getCursor() {
// Select All Query
String selectQuery = "SELECT * FROM " + "data";
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
return cursor;
}
}
编辑编辑编辑 我已在我的清单中设置了权限：
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
感谢您的帮助！
答案 0 :(得分：17)
我认为问题在于db的位置对于不同版本的SDK。请试试这个
private static String DB_PATH = "";
public DataBaseHelper(Context context) {
super(context, DB_NAME, null, 1);// 1? its Database Version
if(android.os.Build.VERSION.SDK_INT >= 4.2){
DB_PATH = context.getApplicationInfo().dataDir + "/databases/";
} else {
DB_PATH = "/data/data/" + context.getPackageName() + "/databases/";
}
this.mContext = context;
}
检查出来
答案 1 :(得分：0)
一个非常疯狂的猜测是你在Android清单中没有所需的权限。此外，我在我的一个项目中使用相同的代码代替checkDatabase（）：
private boolean checkDataBase() {
File dbFile = new File(DATABASE_PATH + DATABASE_NAME);
return dbFile.exists();
}
此外，路径使用：
public static String getDBPath() {
return Environment.getDataDirectory() + "/data/"
+ context.getPackageName() + "/databases/";
}
答案 2 :(得分：0)
我有同样的错误。 我发现在导入和更新数据库中的表时我正在进入数据库。所以我得出结论，如果要更新数据库表，则无法在同一时刻使用它们。