SQLite数据库不起作用

Question

看来我不能将数据插入到我的数据库中，我不知道问题出在哪里。 这里的数据库代码：

public class Database { 
    public static final String KEY_ROWID = "_id"; 
    public static final String KEY_NAME = "Name"; 
    public static final String KEY_PERIOD = "Period"; 
    public static final String KEY_FREQUENCY = "Frequency"; 
    public static final String KEY_RECIEVINGTIME = "Recieving_time"; 
    public static final String KEY_STATS = "Stats"; 

    private static final String DATABASE_NAME = "Reports"; 
    private static final String DATABASE_TABLE = "Table1"; 
    private static final int DATABASE_VERSION = 1; 

    private DbHelper myHelper; 
    private final Context myContext; 
    private SQLiteDatabase myDatabase; 

    private static class DbHelper extends SQLiteOpenHelper{ 

     public DbHelper(Context context) { 
      super(context, DATABASE_NAME, null, DATABASE_VERSION); 
      // TODO Auto-generated constructor stub 
     } 

     @Override 
     public void onCreate(SQLiteDatabase db) { 
      // TODO Auto-generated method stub 
      db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" + 
        KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + 
        KEY_NAME + " TEXT NOT NULL, " + 
        KEY_PERIOD + " TEXT NOT NULL, " + 
        KEY_FREQUENCY + " TEXT NOT NULL, " + 
        KEY_RECIEVINGTIME + " TEXT NOT NULL, " + 
        KEY_STATS + " TEXT NOT NULL);" 
        ); 
     } 

     @Override 
     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
      // TODO Auto-generated method stub 
      db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE); 
      onCreate(db); 
     } 
    } 

    public Database(Context c){ 
     myContext = c; 
    } 

    public Database open(){ 
     myHelper = new DbHelper(myContext); 
     myDatabase = myHelper.getWritableDatabase(); 
     return this; 
    } 

    public void close(){ 
     myDatabase.close(); 
    } 

    public void writeEntry(String name, long period, long frequency, long recievingTime, String stats){ 
     ContentValues cv = new ContentValues(); 
     cv.put(KEY_NAME, name); 
     cv.put(KEY_PERIOD, period); 
     cv.put(KEY_FREQUENCY, frequency); 
     cv.put(KEY_RECIEVINGTIME, recievingTime); 
     cv.put(KEY_STATS, stats); 
     myDatabase.insert(DATABASE_TABLE, null, cv); 
    } 

    public Cursor query(String[] columns, String selection, String[] selectionArgs, String groupBy) { 
     // TODO Auto-generated method stub 
     Cursor c = myDatabase.query(DATABASE_TABLE, columns, selection, selectionArgs, groupBy, null, null); 
     return c; 
    } 
} 

我尝试用这种方法插入数据：

public void save(){ 
    sharedPrefs = context.getSharedPreferences(SPNAME, 0); 
    Log.v(" info", sharedPrefs.getAll().toString()); 
    Database database = new Database(context); 
    database.open(); 
    database.writeEntry(
      sharedPrefs.getString(NAME, "No data was found"), 
      sharedPrefs.getLong(PERIOD, 0), 
      sharedPrefs.getLong(FREQUENCY, 0), 
      sharedPrefs.getLong(RECIEVINGTIME, 0), 
      sharedPrefs.getString(STATS, "No data was found") 
      ); 
    database.close(); 

    editor.remove(NAME); 
    editor.remove(FREQUENCY); 
    editor.remove(RECIEVINGTIME); 
    editor.remove(PERIOD); 
    editor.remove(FREQUENCY); 
    editor.remove(STATS); 
    editor.commit(); 
} 

我用这种方法检索数据：

public ReportItem getReportInfo(String rowId){ 
    ReportItem item = new ReportItem(); 
    database = new Database(context); 
    database.open(); 
    cursor = database.query(new String[]{ 
      Database.KEY_NAME, 
      Database.KEY_PERIOD, 
      Database.KEY_FREQUENCY, 
      Database.KEY_RECIEVINGTIME, 
      Database.KEY_STATS}, Database.KEY_ROWID +" = "+rowId, null, null); 

    if(cursor.moveToFirst()){ 
     item.setName(cursor.getString(cursor.getColumnIndex(Database.KEY_NAME))); 
     item.setPeriod(cursor.getLong(cursor.getColumnIndex(Database.KEY_PERIOD))); 
     item.setFrequency(cursor.getLong(cursor.getColumnIndex(Database.KEY_FREQUENCY))); 
     item.setReceivingTime(cursor.getLong(cursor.getColumnIndex(Database.KEY_RECIEVINGTIME))); 
     item.setStats(cursor.getString(cursor.getColumnIndex(Database.KEY_STATS)));   
    } 
    cursor.close(); 
    database.close(); 
    Log.v("Data from database", item.toString()); 
    return item; 
} 

在save（）方法之前，插入数据到db日志显示：

09-27 17:19:54.973: V/info(31638): <!>com.dailyreports.ainius.Report 75<!> {Period=86400000, Name=report1, Stats=23 24 26 , Frequency=86400000, RecievingTime=62340000} 

但是从检索数据库日志相同的信息后，getReportInfo（String）方法显示：

09-27 17:20:06.263: V/Data from database(31638): <!>com.dailyreports.ainius.Report 117<!> 0 0 0 

有什么建议？提前致谢。

Answer 1

您没有匹配rowId的条目：

Database.KEY_ROWID +" = "+rowId 

所以在getReportInfo()：

1. if(cursor.moveToFirst())返回false，
2. ReportItem item不接受新的值，
3. item返回默认值：空字符串和0l多头。

仔细检查您的值rowId。