在我的应用程序中，我在名为DTUFoodie的assests文件夹中使用现有数据库。打开数据库时，我遇到错误：
08-27 19:36:46.930 5838-5838/com.brainbreaker.dtufoodie E/SQLiteDatabase﹕ Failed to open database '/data/data/com.brainbreaker.dtufoodie/databases/DTUFoodie.db'.
我已经尝试过与此相关的每个问题的解决方案，仍然无法找到问题。 这是我的数据库助手类的代码。
FoodieDatabase.java
public class FoodieDatabase extends SQLiteAssetHelper {
private static String DB_PATH = "/data/data/com.brainbreaker.dtufoodie/databases/";
public String DATABASE_CREATE = "create table "
+ TableData.TableInfo.TABLE_NAME + "("
+ TableData.TableInfo.COLUMN_ID + " INTEGER primary key ,"
+ TableData.TableInfo.COLUMN_hostel + " TEXT not null,"
+ TableData.TableInfo.COLUMN_weekday + " TEXT not null,"
+ TableData.TableInfo.COLUMN_category + " TEXT not null,"
+ TableData.TableInfo.COLUMN_food + " TEXT not null,"
+ TableData.TableInfo.COLUMN_rate + " TEXT not null" + ")";
private static final int DATABASE_VERSION = 1;
private SQLiteDatabase dtufoodie;
Context mycontext;
private static String DB_NAME = TableData.TableInfo.DATABASE_NAME;
// Database creation sql statement
public FoodieDatabase(Context context) {
super(context, TableData.TableInfo.DATABASE_NAME, null, DATABASE_VERSION);
this.mycontext = context;
Log.w("FoodieDatabase", "Database Created");
}
// @Override
// public void onCreate(SQLiteDatabase database) {
// database.execSQL(DATABASE_CREATE);
// Log.w(FoodieDatabase.class.getName(),
// " Table " + TableData.TableInfo.TABLE_NAME + " Successfully created. "
// );
// }
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
public void insertvalues(FoodieDatabase fdb, Integer id, String hostel,
String weekday, String category, String food, String rate) {
SQLiteDatabase sdb = fdb.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put(TableData.TableInfo.COLUMN_ID, id);
cv.put(TableData.TableInfo.COLUMN_hostel, hostel);
cv.put(TableData.TableInfo.COLUMN_weekday, weekday);
cv.put(TableData.TableInfo.COLUMN_category, category);
cv.put(TableData.TableInfo.COLUMN_food, food);
cv.put(TableData.TableInfo.COLUMN_rate, rate);
sdb.insert(TableData.TableInfo.TABLE_NAME, null, cv);
}
public Cursor retrievevalues(FoodieDatabase fdb) {
SQLiteDatabase sq = fdb.getReadableDatabase();
String[] columns = {TableData.TableInfo.COLUMN_ID,
TableData.TableInfo.COLUMN_hostel,
TableData.TableInfo.COLUMN_weekday,
TableData.TableInfo.COLUMN_category,
TableData.TableInfo.COLUMN_food,
TableData.TableInfo.COLUMN_rate};
Cursor CR = sq.query(TableData.TableInfo.TABLE_NAME, columns, null, null, null, null, null);
return CR;
}
/**
* 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;
dtufoodie = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}
@Override
public synchronized void close() {
if (dtufoodie != null)
dtufoodie.close();
super.close();
}
}
UsingActivity.java
public class Home extends Activity {
Context context= this;
String food;
String hostelname;
String category;
String rate;
String weekday;
private Toolbar toolbar;
private DrawerView drawer;
private ActionBarDrawerToggle drawerToggle;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
DrawerLayout drawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout);
toolbar = (Toolbar) findViewById(R.id.toolbar);
drawer = (DrawerView) findViewById(R.id.drawer);
setSupportActionBar(toolbar);
// Database Operations
// FoodieDatabase fdb = new FoodieDatabase(this);
FoodieDatabase myDbHelper = new FoodieDatabase(this);
try {
myDbHelper.createDataBase();
}
catch (IOException ioe) {
throw new Error("Unable to create database");
}
try {
myDbHelper.openDataBase();
}
catch(SQLException sqle){
throw new Error("SQLException: "+sqle);
}
Cursor CR = myDbHelper.retrievevalues(myDbHelper);
CR.moveToFirst();
do {
hostelname = "ABH";
category = CR.getString(1);
food = CR.getString(2);
weekday = CR.getString(3);
rate = CR.getString(4);
Toast.makeText(Home.this, category, Toast.LENGTH_SHORT).show();
Toast.makeText(Home.this, weekday, Toast.LENGTH_SHORT).show();
}
while(CR.moveToNext());
}}
这是logcat：
08-27 19:36:46.926 5838-5838/com.brainbreaker.dtufoodie W/FoodieDatabase﹕ Database Created
08-27 19:36:46.927 5838-5838/com.brainbreaker.dtufoodie E/SQLiteLog﹕ (14) cannot open file at line 30191 of [00bb9c9ce4]
08-27 19:36:46.927 5838-5838/com.brainbreaker.dtufoodie E/SQLiteLog﹕ (14) os_unix.c:30191: (2) open(/data/data/com.brainbreaker.dtufoodie/databases/DTUFoodie.db) -
08-27 19:36:46.930 5838-5838/com.brainbreaker.dtufoodie E/SQLiteDatabase﹕ Failed to open database '/data/data/com.brainbreaker.dtufoodie/databases/DTUFoodie.db'.
android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:209)
at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:193)
at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:463)
at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:185)
at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:177)
at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:804)
at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:789)
at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:694)
at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:669)
at com.brainbreaker.dtufoodie.database.FoodieDatabase.checkDataBase(FoodieDatabase.java:128)
at com.brainbreaker.dtufoodie.database.FoodieDatabase.createDataBase(FoodieDatabase.java:94)
at com.brainbreaker.dtufoodie.Home.onCreate(Home.java:78)
at android.app.Activity.performCreate(Activity.java:5248)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1110)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2162)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2257)
at android.app.ActivityThread.access$800(ActivityThread.java:139)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5086)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
08-27 19:36:46.930 5838-5838/com.brainbreaker.dtufoodie W/SQLiteAssetHelper﹕ copying database from assets...
08-27 19:36:46.933 5838-5838/com.brainbreaker.dtufoodie E/SQLiteAssetHelper﹕ Couldn't open DTUFoodie.db for writing (will try read-only):
com.readystatesoftware.sqliteasset.SQLiteAssetHelper$SQLiteAssetException: Missing databases/DTUFoodie.db file (or .zip, .gz archive) in assets, or target folder not writable
at android.content.res.AssetManager.openAsset(Native Method)
at android.content.res.AssetManager.open(AssetManager.java:316)
at android.content.res.AssetManager.open(AssetManager.java:290)
at com.readystatesoftware.sqliteasset.SQLiteAssetHelper.copyDatabaseFromAssets(SQLiteAssetHelper.java:436)
at com.readystatesoftware.sqliteasset.SQLiteAssetHelper.createOrOpenDatabase(SQLiteAssetHelper.java:400)
at com.readystatesoftware.sqliteasset.SQLiteAssetHelper.getWritableDatabase(SQLiteAssetHelper.java:176)
at com.readystatesoftware.sqliteasset.SQLiteAssetHelper.getReadableDatabase(SQLiteAssetHelper.java:254)
at com.brainbreaker.dtufoodie.database.FoodieDatabase.createDataBase(FoodieDatabase.java:102)
at com.brainbreaker.dtufoodie.Home.onCreate(Home.java:78)
at android.app.Activity.performCreate(Activity.java:5248)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1110)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2162)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2257)
at android.app.ActivityThread.access$800(ActivityThread.java:139)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5086)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
08-27 19:36:46.933 5838-5838/com.brainbreaker.dtufoodie E/SQLiteLog﹕ (14) cannot open file at line 30191 of [00bb9c9ce4]
08-27 19:36:46.933 5838-5838/com.brainbreaker.dtufoodie E/SQLiteLog﹕ (14) os_unix.c:30191: (2) open(/data/data/com.brainbreaker.dtufoodie/databases/DTUFoodie.db) -
08-27 19:36:46.936 5838-5838/com.brainbreaker.dtufoodie E/SQLiteDatabase﹕ Failed to open database '/data/data/com.brainbreaker.dtufoodie/databases/DTUFoodie.db'.
感谢任何帮助。提前谢谢。
答案 0 :(得分：1)
我遇到了同样的问题。我的解决方案是将数据库放在正确的文件夹中。
将您的db文件放在/src/main/assets/databases/your_db_file.db
答案 1 :(得分：0)
Intenta：``SQLiteDatabase.OPEN_READWRITE''
iDiff = cint((Date() - ServiceDate)/365) 'Gives the number of years between the ServiceDate and today
dMostRecent = DateAdd("yyyy",iDiff, ServiceDate) 'Uses the mm/dd from ServiceDate, but makes it the current year
If dMostRecent > Date() then 'If the new date is in the future...
dMostRecent = DateAdd("yyyy",-1,dMostRecent) 'Subtract 1 year
End If
'dMostRecent should now be within the last 12 months and I can check the dates that the given course was last taken and compare
答案 2 :(得分：-1)
它的文件问题（.db文件），我通过以经典（最原始）的方式将.db文件压缩为.zip文件解决了这个问题。