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我目前正在为 Android SDK 创建一个应用程序,它将允许我打开/复制已经在应用程序之外创建的数据库。我无法让我的程序读取数据库中的表。遵循关于 question 的一些建议我之前发帖,我写了一个类,直接调用SQLiteDatabase,并在Android SDK自带的sqlite3版本中创建我的数据库。现在,出于某种原因,我的程序甚至无法打开数据库。它似乎认识到它在那里,但 Logcat(我正在使用 Eclipse Juno 和 ADT 插件)现在一直告诉我它“无法打开数据库”。任何人都知道问题可能是什么?
这是我所有的代码(为了完整起见):
public class MyDatabase
{
private static final String TABLE_OS = "OregonState";
private static final String COLUMN_ID = "_id";
private static final String COLUMN_NAME = "Name";
private static final String COLUMN_FIELD = "Field";
SQLiteDatabase database;
String path;
public MyDatabase()
{
File file = new File("/scratch/android-sdk-linux/tools/os.sqlite");
database = SQLiteDatabase.openOrCreateDatabase(file, null);
path = database.getPath();
database.close();
}
public long insert(ContentValues values, String name, String field)
{
database = SQLiteDatabase.openDatabase(path, null, SQLiteDatabase.OPEN_READWRITE);
values.put("Name", name);
values.put("Field", field);
long id = database.insert(TABLE_OS, null, values);
database.close();
return id;
}
public long insert(ContentValues values, String name)
{
database = SQLiteDatabase.openDatabase(path, null, SQLiteDatabase.OPEN_READWRITE);
values.put("Name", name);
long id = database.insert(TABLE_OS, null, values);
database.close();
return id;
}
public int delete(int id)
{
database = SQLiteDatabase.openDatabase(path, null, SQLiteDatabase.OPEN_READWRITE);
database.delete(TABLE_OS, COLUMN_ID + "=" + id, null);
database.close();
return 1;
}
public int update(ContentValues values, int id, String name, String field)
{
database = SQLiteDatabase.openDatabase(path, null, SQLiteDatabase.OPEN_READWRITE);
values.put("Name", name);
values.put("Field", field);
database.update(TABLE_OS, values, COLUMN_ID + "=" + id, null);
database.close();
return 1;
}
public int update(ContentValues values, int id, String name)
{
database = SQLiteDatabase.openDatabase(path, null, SQLiteDatabase.OPEN_READWRITE);
values.put("Name", name);
database.update(TABLE_OS, values, COLUMN_ID + "=" + id, null);
database.close();
return 1;
}
public Cursor get(int id)
{
return database.query(TABLE_OS, new String[] {COLUMN_ID, COLUMN_NAME, COLUMN_FIELD}, COLUMN_ID + "=" + id, null, null, null, null);
}
public Cursor getAll()
{
return database.query(TABLE_OS, new String[] {COLUMN_ID, COLUMN_NAME, COLUMN_FIELD}, null, null, null, null, null);
}
}
public class SQLTest extends Activity
{
SQLAdapter adapter;
MyDatabase database;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sqltest);
database = new MyDatabase();
database.getAll();
}
@Override
public boolean onCreateOptionsMenu(Menu menu)
{
getMenuInflater().inflate(R.menu.activity_sqltest, menu);
return true;
}
public long insert(String name, String field)
{
ContentValues values = new ContentValues();
long id = database.insert(values, name, field);
return id;
}
public long insert(String name)
{
ContentValues values = new ContentValues();
long id = database.insert(values, name);
return id;
}
public int delete(int id)
{
int rowsDeleted = database.delete(id);
return rowsDeleted;
}
public int update(int id, String name, String field)
{
ContentValues values = new ContentValues();
int rowsUpdated = database.update(values, id, name, field);
return rowsUpdated;
}
public int update(int id, String name)
{
ContentValues values = new ContentValues();
int rowsUpdated = database.update(values, id, name);
return rowsUpdated;
}
public void get(int id)
{
Cursor cursor = database.get(id);
TextView tv = new TextView(this);
String table = "";
if (cursor.moveToFirst())
table += "\n" + cursor.getString(0) + " " + cursor.getString(1) + " " + cursor.getString(2);
else
table += "No hall found with ID: " + id;
tv.setText(table);
setContentView(tv);
cursor.close();
}
public void getAll()
{
TextView tv = new TextView(this);
String table = "";
try
{
Cursor cursor = database.getAll();
if (cursor.moveToFirst())
{
do
{
table += "\n" + cursor.getString(0) + " " + cursor.getString(1) + " " + cursor.getString(2);
} while (cursor.moveToNext());
}
cursor.close();
} catch (Exception e) {}
tv.setText(table);
setContentView(tv);
}
}
这也是我的 Logcat 日志:
07-16 15:27:08.364: E/Trace(810): error opening trace file: No such file or directory (2)
07-16 15:27:08.504: E/SQLiteLog(810): (14) cannot open file at line 30174 of [00bb9c9ce4]
07-16 15:27:08.504: E/SQLiteLog(810): (14) os_unix.c:30174: (2) open(/scratch/android-sdk-linux/tools/os.sqlite) -
07-16 15:27:08.524: E/SQLiteDatabase(810): Failed to open database '/scratch/android-sdk-linux/tools/os.sqlite'.
07-16 15:27:08.524: E/SQLiteDatabase(810): android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:209)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:193)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:463)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:185)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:177)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:804)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:789)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:694)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:709)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:702)
07-16 15:27:08.524: E/SQLiteDatabase(810): at com.example.sql2.MyDatabase.<init>(MyDatabase.java:26)
07-16 15:27:08.524: E/SQLiteDatabase(810): at com.example.sql2.SQLTest.onCreate(SQLTest.java:20)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.app.Activity.performCreate(Activity.java:5008)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.app.ActivityThread.access$600(ActivityThread.java:130)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.os.Handler.dispatchMessage(Handler.java:99)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.os.Looper.loop(Looper.java:137)
07-16 15:27:08.524: E/SQLiteDatabase(810): at android.app.ActivityThread.main(ActivityThread.java:4745)
07-16 15:27:08.524: E/SQLiteDatabase(810): at java.lang.reflect.Method.invokeNative(Native Method)
07-16 15:27:08.524: E/SQLiteDatabase(810): at java.lang.reflect.Method.invoke(Method.java:511)
07-16 15:27:08.524: E/SQLiteDatabase(810): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
07-16 15:27:08.524: E/SQLiteDatabase(810): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
07-16 15:27:08.524: E/SQLiteDatabase(810): at dalvik.system.NativeStart.main(Native Method)
07-16 15:27:08.524: D/AndroidRuntime(810): Shutting down VM
07-16 15:27:08.524: W/dalvikvm(810): threadid=1: thread exiting with uncaught exception (group=0x40a13300)
07-16 15:27:08.534: E/AndroidRuntime(810): FATAL EXCEPTION: main
07-16 15:27:08.534: E/AndroidRuntime(810): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.sql2/com.example.sql2.SQLTest}: android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
07-16 15:27:08.534: E/AndroidRuntime(810): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.app.ActivityThread.access$600(ActivityThread.java:130)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.os.Handler.dispatchMessage(Handler.java:99)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.os.Looper.loop(Looper.java:137)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.app.ActivityThread.main(ActivityThread.java:4745)
07-16 15:27:08.534: E/AndroidRuntime(810): at java.lang.reflect.Method.invokeNative(Native Method)
07-16 15:27:08.534: E/AndroidRuntime(810): at java.lang.reflect.Method.invoke(Method.java:511)
07-16 15:27:08.534: E/AndroidRuntime(810): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
07-16 15:27:08.534: E/AndroidRuntime(810): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
07-16 15:27:08.534: E/AndroidRuntime(810): at dalvik.system.NativeStart.main(Native Method)
07-16 15:27:08.534: E/AndroidRuntime(810): Caused by: android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
07-16 15:27:08.534: E/AndroidRuntime(810): at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:209)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:193)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:463)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:185)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:177)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:804)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:789)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:694)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:709)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:702)
07-16 15:27:08.534: E/AndroidRuntime(810): at com.example.sql2.MyDatabase.<init>(MyDatabase.java:26)
07-16 15:27:08.534: E/AndroidRuntime(810): at com.example.sql2.SQLTest.onCreate(SQLTest.java:20)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.app.Activity.performCreate(Activity.java:5008)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
07-16 15:27:08.534: E/AndroidRuntime(810): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
07-16 15:27:08.534: E/AndroidRuntime(810): ... 11 more
最佳答案
将此权限添加到您的项目
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
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