这是我的DatabaseHelper，我正在尝试连接到我的数据库文件（db.sql）：
public class DatabaseHelper extends SQLiteOpenHelper {
private final static String TAG = "DatabaseHelper";
private final Context myContext;
private static final String DATABASE_NAME = "db.sql";
private static final int DATABASE_VERSION = 1;
private String pathToSaveDBFile;
public DatabaseHelper(Context context, String filePath) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
this.myContext = context;
pathToSaveDBFile = new StringBuffer(filePath).append("/").append(DATABASE_NAME).toString();
}
public void prepareDatabase() throws IOException {
boolean dbExist = checkDataBase();
if(dbExist) {
Log.d(TAG, "Database exists.");
int currentDBVersion = 1;
if (DATABASE_VERSION > currentDBVersion) {
Log.d(TAG, "Database version is higher than old.");
deleteDb();
try {
copyDataBase();
} catch (IOException e) {
Log.e(TAG, e.getMessage());
}
}
} else {
try {
copyDataBase();
} catch (IOException e) {
Log.e(TAG, e.getMessage());
}
}
}
private boolean checkDataBase() {
boolean checkDB = false;
try {
File file = new File(pathToSaveDBFile);
checkDB = file.exists();
} catch(SQLiteException e) {
Log.d(TAG, e.getMessage());
}
return checkDB;
}
private void copyDataBase() throws IOException {
OutputStream os = new FileOutputStream(pathToSaveDBFile);
InputStream is = myContext.getAssets().open("sqlite/"+DATABASE_NAME);
byte[] buffer = new byte[1024];
int length;
while ((length = is.read(buffer)) > 0) {
os.write(buffer, 0, length);
}
is.close();
os.flush();
os.close();
}
public void deleteDb() {
File file = new File(pathToSaveDBFile);
if(file.exists()) {
file.delete();
Log.d(TAG, "Database deleted.");
}
}
@Override
public void onCreate(SQLiteDatabase db) {
Log.d(TAG, "onCreate");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
if (newVersion > oldVersion)
{
Log.v("Database Upgrade", "Database version higher than old.");
deleteDb();
}
}
public List<Office> getOffices() {
SQLiteDatabase db = SQLiteDatabase.openDatabase(pathToSaveDBFile, null, SQLiteDatabase.OPEN_READONLY);
String query = "SELECT ID, NAME, IMG , LOCATION FROM Offices";
Cursor cursor = db.rawQuery(query, null);
List<Office> list = new ArrayList<Office>();
while(cursor.moveToNext()) {
Office office = new Office();
office.setOfficeID(cursor.getInt(0));
office.setOfficeName(cursor.getString(1));
office.setOfficeImg(cursor.getInt(2));
office.setOfficeLocation(cursor.getString(3));
list.add(office);
}
db.close();
return list;
}}
我的数据库包含一个表（办公室），其中包含四行：ID，名称，图像和位置。
当我在午餐时，应用程序崩溃，我收到错误“没有这样的表：办公室” 我试图从Stackoverflow的其他答案中解决错误，但不幸的是没有任何作用，仍然有相同的错误。
这是跟踪轨迹：
03-11 16:39:32.872 4352-4352/com.artline.ministryoftourismpalestine E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.artline.ministryoftourismpalestine, PID: 4352
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.artline.ministryoftourismpalestine/com.artline.ministryoftourismpalestine.Offices}: android.database.sqlite.SQLiteException: no such table: Offices (code 1): , while compiling: SELECT ID, NAME, IMG , LOCATION FROM Offices
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2778)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6494)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
Caused by: android.database.sqlite.SQLiteException: no such table: Offices (code 1): , while compiling: SELECT ID, NAME, IMG , LOCATION FROM Offices
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:890)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:501)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:46)
at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1392)
at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1331)
at com.artline.ministryoftourismpalestine.DatabaseHelper.getOffices(DatabaseHelper.java:107)
at com.artline.ministryoftourismpalestine.Offices.showData(Offices.java:77)
at com.artline.ministryoftourismpalestine.Offices.onCreate(Offices.java:48)
at android.app.Activity.performCreate(Activity.java:7009)
at android.app.Activity.performCreate(Activity.java:7000)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2731)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2856)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1589)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6494)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
请帮我解决错误......
答案 0 :(得分：0)
您需要将数据库从资产文件夹复制到应用程序内部存储中。然后，您可以从内部存储中读取数据库。
df = pd.DataFrame({
'value': list(range(10, 19))
})
df = df.reset_index()
.set_index([df.index % 5, df.index // 5])
.unstack().sort_index(axis=1, level=1)
df.columns = df.columns.map('{0[0]}_{0[1]}'.format)
print (df)
index_0 value_0 index_1 value_1
0 0.0 10.0 5.0 15.0
1 1.0 11.0 6.0 16.0
2 2.0 12.0 7.0 17.0
3 3.0 13.0 8.0 18.0
4 4.0 14.0 NaN NaN