SQLiteCantOpenDatabaseException：未知错误（代码 14 SQLITE_CANTOPEN）：无法打开数据库

Question

我正在使用以下代码打开或创建一个 sqlite 数据库。该代码在某些手机上运行良好，但在 Android P 设备上出现以下错误。

SQLiteDatabase myDB = null;
myDB = backup.this.openOrCreateDatabase(url[0], MODE_PRIVATE, null);

Logcat

2019-11-14 07:49:56.204 10213-10363/com.gadha.garden E/SQLiteLog: (14) cannot open file at line 36667 of [c255889bd9]
2019-11-14 07:49:56.204 10213-10363/com.gadha.garden E/SQLiteLog: (14) os_unix.c:36667: (2) open(/sdcard/Download/2019-11-14 07-49-56 AM.db) - 
2019-11-14 07:49:56.241 10213-10363/com.gadha.garden E/SQLiteDatabase: Failed to open database '/sdcard/Download/2019-11-14 07-49-56 AM.db'.
    android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14 SQLITE_CANTOPEN): Could not open database
        at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
        at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:211)
        at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:195)
        at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:503)
        at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:204)
        at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:196)
        at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:880)
        at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:865)
        at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:766)
        at android.app.ContextImpl.openOrCreateDatabase(ContextImpl.java:772)
        at android.app.ContextImpl.openOrCreateDatabase(ContextImpl.java:757)
        at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:306)
        at com.gadha.garden.backup$backupRestore.doInBackground(backup.java:120)
        at com.gadha.garden.backup$backupRestore.doInBackground(backup.java:108)
        at android.os.AsyncTask.call(AsyncTask.java:333)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
        at java.lang.Thread.run(Thread.java:764)

Answer 1

正在考虑评论

I am trying to create a database. How can use disableWriteAheadLogging before creating a database? –

那么我相信你的问题是你没有授予所需的权限，即使你说你有 :-

Added both read and write permissions.

您需要授予 WRITE_EXTERNAL_STORAGE（这隐含授予 READ_EXTERNAL_STORAGE）。

对于设备 API 23+ Android 6+ 而不是 9+ 这需要通过 MANIFEST 授予权限，例如:-

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

而且用户根据 Permission approval授予访问权限。对于小于 API 23 的设备，只需要清单许可。

例子

以下是一个简单的例子，boh 重现了这个问题并表明授予权限可以解决问题。

清单包含上述 使用权限 条目。

通过以下方式重新获得用户权限 (ExternalStoragePermissions.java) :-

abstract class ExternalStoragePermissions {

    private static final int REQUEST_EXTERNAL_STORAGE = 1;
    private static String[] PERMISSIONS_STORAGE = {
            Manifest.permission.WRITE_EXTERNAL_STORAGE
    };

    public ExternalStoragePermissions(Activity callingActivity) {}
    // Note call this method
    public static void verifyStoragePermissions(Activity activity) {
        int permission = ActivityCompat.checkSelfPermission(
                activity,
                Manifest.permission.WRITE_EXTERNAL_STORAGE);

        if(permission != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(
                    activity,
                    PERMISSIONS_STORAGE,
                    REQUEST_EXTERNAL_STORAGE
            );
        }
    }
}

使用的activity(MainActivity.java)是:-

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if(Build.VERSION.SDK_INT >= 23) {
            ExternalStoragePermissions.verifyStoragePermissions(this);
        }

        SQLiteDatabase myDB = null;
        myDB = this.openOrCreateDatabase("/sdcard/Download/2019-11-14 07-49-56 AM.db", MODE_PRIVATE, null);
        DatabaseUtils.dumpCursor(
                myDB.query("sqlite_master",null,null,null,null,null,null)
        );
        myDB.close();
    }
}

结果

当运行 App 第一次显示时：-

但是当主线程继续并且访问未被授予时，日志包括：-

2019-11-15 08:35:33.439 11874-11874/a.so58855993copyfromassets D/AndroidRuntime: Shutting down VM
2019-11-15 08:35:33.440 11874-11874/a.so58855993copyfromassets E/AndroidRuntime: FATAL EXCEPTION: main
    Process: a.so58855993copyfromassets, PID: 11874
    java.lang.RuntimeException: Unable to start activity ComponentInfo{a.so58855993copyfromassets/a.so58855993copyfromassets.MainActivity}: android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14 SQLITE_CANTOPEN): Could not open database
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3270)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3409)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
     Caused by: android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14 SQLITE_CANTOPEN): Could not open database
        at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
        at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:215)
        at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:197)
        at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:505)
        at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:206)
        at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:198)
        at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:915)
        at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:895)
        at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:786)
        at android.app.ContextImpl.openOrCreateDatabase(ContextImpl.java:812)
        at android.app.ContextImpl.openOrCreateDatabase(ContextImpl.java:797)
        at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:310)
        at a.so58855993copyfromassets.MainActivity.onCreate(MainActivity.java:27)
        at android.app.Activity.performCreate(Activity.java:7802)
        at android.app.Activity.performCreate(Activity.java:7791)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1299)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3245)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3409) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83) 
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016) 
        at android.os.Handler.dispatchMessage(Handler.java:107) 
        at android.os.Looper.loop(Looper.java:214) 
        at android.app.ActivityThread.main(ActivityThread.java:7356) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

但是在这个阶段，应用程序仍然处于活动状态，因为请求权限的对话框仍然处于活动状态。单击允许导致应用程序崩溃，但随后重新启动并根据包含的日志成功创建数据库：-

2019-11-15 08:41:13.615 I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@5df21a1
2019-11-15 08:41:13.616 I/System.out: 0 {
2019-11-15 08:41:13.616 I/System.out:    type=table
2019-11-15 08:41:13.616 I/System.out:    name=android_metadata
2019-11-15 08:41:13.616 I/System.out:    tbl_name=android_metadata
2019-11-15 08:41:13.616 I/System.out:    rootpage=3
2019-11-15 08:41:13.616 I/System.out:    sql=CREATE TABLE android_metadata (locale TEXT)
2019-11-15 08:41:13.616 I/System.out: }
2019-11-15 08:41:13.616 I/System.out: <<<<<

注意以上仅为演示。在要使用的应用程序中，您显然会在尝试访问数据库之前设置权限。
理想情况下，您不应该对路径进行硬编码，而是使用系统值，例如Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS) 为路径。
通常，您会通过 Context 的 getDatabasePath 方法将数据库放在应用程序的数据中，而不是将数据集放在下载文件夹中。
- 应用程序数据中标准位置的权限已授予，因此无需请求。

SQLiteCantOpenDatabaseException：未知错误（代码 14 SQLITE_CANTOPEN）：无法打开数据库

SQLiteCantOpenDatabaseException: unknown error (code 14 SQLITE_CANTOPEN): Could not open database

android

sqlite

android-9.0-pie

例子

结果