無法打開sqlite數據庫文件

Question

有人可以幫我解釋錯誤不斷出現的原因。

我在我的活動中有spinners和EditTexts。在該活動中，它已經顯示出android.database.sqlite.SQLiteCantOpenDatabaseException：無法打開數據庫文件。

這裏是我的logcat的說：

07-03 16:43:03.156: E/SqliteDatabaseCpp(13449): sqlite3_open_v2("/data/data/ph.com.unilab.ireport/databases/lamp_db.sqlite", &handle, 1, NULL) failed 
07-03 16:43:03.164: E/SQLiteDatabase(13449): Failed to open the database. closing it. 
07-03 16:43:03.164: E/SQLiteDatabase(13449): android.database.sqlite.SQLiteCantOpenDatabaseException: unable to open database file 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at android.database.sqlite.SQLiteDatabase.dbopen(Native Method) 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:1123) 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:1074) 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:1050) 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at ph.com.unilab.ireport.DatabaseHandler.checkDataBase(DatabaseHandler.java:81) 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at ph.com.unilab.ireport.DatabaseHandler.createDB(DatabaseHandler.java:49) 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at ph.com.unilab.ireport.S_9th_ISubmit.onCreate(S_9th_ISubmit.java:56) 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at android.app.Activity.performCreate(Activity.java:4465) 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1053) 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1934) 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1995) 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at android.app.ActivityThread.access$600(ActivityThread.java:128) 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1161) 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at android.os.Handler.dispatchMessage(Handler.java:99) 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at android.os.Looper.loop(Looper.java:137) 
07-03 16:43:03.164: E/SQLiteDatabase(13449): at android.app.ActivityThread.main(ActivityThread.java:4514) 

我可以從數據庫中微調填充數據，但不過，無論我按保存按鈕，從控件的值沒有保存到數據庫。

databaseHandler.java

public class DatabaseHandler extends SQLiteOpenHelper { 
static final String TAG = "LAMP"; 
public SQLiteDatabase db; 
private final Context myContext;  
private static DatabaseHandler dbHandler; 


public DatabaseHandler(Context context) { 
    super(context, Constants.DB_NAME, null, Constants.DB_VERSION); 
    this.myContext = context; 
} 

public static DatabaseHandler getInstance(Context context) { 
     if(dbHandler == null) { 
     dbHandler = new DatabaseHandler(context); 
     } 
    return dbHandler; 
    } 


    public void createDB() throws IOException{ 
    boolean dbExist = checkDataBase(); 
    if(dbExist) { 
      //do nothing - database already exist 
    }else{ 
     this.getReadableDatabase(); 
     try { 
      copyDataBase(); 
     } catch (IOException e) { 
      throw new Error("Error copying database"); 
     } 
    } 
} 


    private boolean checkDataBase(){ 
    SQLiteDatabase checkDB = null; 
    try{ 
      String myPath =Constants.DB_PATH + Constants.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; 
    } 


    private void copyDataBase() throws IOException{ 

     //Open your local db as the input stream 
     InputStream myInput = myContext.getAssets().open(Constants.DB_NAME); 

     // Path to the just created empty db 
     String outFileName = Constants.DB_PATH + Constants.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 = Constants.DB_PATH + Constants.DB_NAME; 
     db = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY); 

    } 

    @Override 
    public synchronized void close() { 

      if(db != null) 
       db.close(); 

      super.close(); 

    } 

    @Override 
    public void onCreate(SQLiteDatabase db) { 

    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 

    } 

你能幫助解決這個問題？

Answer 1

正如dasdasd說，使用

this.getWritableDatabase();
代替
this.getReadableDatabase();

而且，創建的onCreate數據庫。 OnCreate在數據庫首次創建時被調用。這是創建表格和表格的初始人口應該發生的地方。

例如

@Override 
public void onCreate(SQLiteDatabase db) { 
    db.execSQL("CREATE TABLE IF NOT EXISTS " + tableName + "(" + id 
      + " INTEGER PRIMARY KEY AUTOINCREMENT, " + startDate 
      + " LONG , " + url + " TEXT, " + title + " TEXT, " + endDate 
      + " LONG, " + sentToCloud + " INTEGER DEFAULT 0);"); 

} 

Answer 2

你有這樣一行：

this.getReadableDatabase(); 

你可以用這個方法寫的。

它改成這樣：

this.getWritableDatabase();