Question

我知道问题已被多次询问，但我找不到我的错误。我想在创建表时我做的一切都是正确的。

错误消息是：

android.database.sqlite.SQLiteException：table GPSLocation没有名为Number的列（代码1）：

我多次检查空白和标点符号。请帮我找出错误。

这是我的数据库类：

private GPSDatabase(Context context) {
    super(context, DB_NAME, null, VERSION);
}


public static GPSDatabase getInstance (final Context context){
    if (INSTANCE == null){
        INSTANCE = new GPSDatabase(context);
    }
    return INSTANCE;
}

我在这里创建表

@Override
public void onCreate(final SQLiteDatabase db) {

    String createQuery =
            "CREATE TABLE " + TABLE_NAME + " (" + ID_COLUMN + " INTEGER PRIMARY KEY, " + NUMBER_COLUMN + " INTEGER DEFAULT NULL, " + DISTANCE_COLUMN + " INTEGER DEFAULT NULL, " + LATITUDE_COLUMN + " REAL DEFAULT NULL, " + LONGITUDE_COLUMN + " REAL DEFAULT NULL)";

    db.execSQL(createQuery);
    Log.d(TAG, "Table created");
}

onUpgrade（）方法会破坏现有的表

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    String dropTable = "DROP TABLE IF EXISTS " + TABLE_NAME;
    db.execSQL(dropTable);

    Log.d(TAG,"Table deleted");
    onCreate(db);
}

创建新的数据库条目

public GPSLocation createGPSLocation (final GPSLocation loc){

    long newID = -1;

    try{
        Log.d(TAG,"createGPSLocation begin");
        SQLiteDatabase db = getWritableDatabase();

        ContentValues values = new ContentValues();

        values.put(NUMBER_COLUMN, loc.getNumber());
        values.put(DISTANCE_COLUMN, loc.getDistance());
        values.put(LATITUDE_COLUMN, loc.getLatitude());
        values.put(LONGITUDE_COLUMN, loc.getLongitude());

        newID = db.insert(TABLE_NAME, null, values);

        db.close();
    }catch (SQLiteException e){
        Log.e(TAG,"insert");
    }finally {
        Log.d(TAG,"insert with ID " + newID);
    }


    Log.d(TAG, "createGPSLocation successful");
    return readGPSLocation(newID);
}

public GPSLocation readGPSLocation(final long id) {
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.query(TABLE_NAME, new String[]{ID_COLUMN, NUMBER_COLUMN, DISTANCE_COLUMN,
            LATITUDE_COLUMN, LONGITUDE_COLUMN}, ID_COLUMN + " = ?", new String[]{String.valueOf(id)}, null, null, null);

    GPSLocation loc = null;

    if (cursor != null && cursor.getCount() > 0) {
        cursor.moveToFirst();

        loc = new GPSLocation(cursor.getInt(cursor.getColumnIndex(NUMBER_COLUMN)));

        loc.setId(cursor.getLong(cursor.getColumnIndex(ID_COLUMN)));
        loc.setDistance(cursor.getInt(cursor.getColumnIndex(DISTANCE_COLUMN)));
        loc.setLatitude(cursor.getDouble(cursor.getColumnIndex(LATITUDE_COLUMN)));
        loc.setLongitude(cursor.getDouble(cursor.getColumnIndex(LATITUDE_COLUMN)));

    }

    db.close();

    Log.d(TAG, "read");
    return loc;
}
}

Answer 1

下面是更新后的代码：

<ModelMapping>

你的bean类：

<ModelMapping>

的活动：

public class GPSDatabase extends SQLiteOpenHelper {
    public static final String DB_NAME = "GPSDatabase";
        public static final int VERSION = 1;
        public static final String TABLE_NAME = "GPSLocation";
        public static final String ID_COLUMN = "id";
        public static final String NUMBER_COLUMN = "number";
        public static final String DISTANCE_COLUMN = "distance";
        public static final String LATITUDE_COLUMN = "latitude";
        public static final String LONGITUDE_COLUMN = "longitude";
        public static final String TAG = "GPSDatabase";


        public GPSDatabase(Context context) {
            super(context, DB_NAME, null, VERSION);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {

            String createQuery =
                    "CREATE TABLE IF NOT EXISTS " + TABLE_NAME + " (" + ID_COLUMN + " INTEGER PRIMARY KEY, " + NUMBER_COLUMN + " INTEGER DEFAULT NULL, " + DISTANCE_COLUMN + " INTEGER DEFAULT NULL, " + LATITUDE_COLUMN + " REAL DEFAULT NULL, " + LONGITUDE_COLUMN + " REAL DEFAULT NULL)";

            db.execSQL(createQuery);
            Log.d(TAG, "Table created");

        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int i, int i1) {

            String dropTable = "DROP TABLE IF EXISTS " + TABLE_NAME;
            db.execSQL(dropTable);

            Log.d(TAG, "Table deleted");
            onCreate(db);

        }

        public GPSLocation createGpsLocation(GPSLocation loc) {

            SQLiteDatabase sqLiteDatabase = this.getWritableDatabase();
            long newID = -1;

            try {
                Log.d(TAG, "createGPSLocation begin");

                ContentValues values = new ContentValues();

                values.put(NUMBER_COLUMN, loc.getNumber());
                values.put(DISTANCE_COLUMN, loc.getDistance());
                values.put(LATITUDE_COLUMN, loc.getLatitude());
                values.put(LONGITUDE_COLUMN, loc.getLongitude());

                newID = sqLiteDatabase.insert(TABLE_NAME, null, values);

                sqLiteDatabase.close();
            } catch (SQLiteException e) {
                Log.e(TAG, "insert");
            } finally {
                Log.d(TAG, "insert with ID " + newID);
            }
            Log.d(TAG, "createGPSLocation successful");
            return loc;
        }

        public GPSLocation readGPSLocation(final long id) {
            SQLiteDatabase db = this.getReadableDatabase();
            GPSLocation loc = null;
            String query = "SELECT * FROM " + TABLE_NAME + " where id= " + ID_COLUMN;
            Cursor cursor = db.rawQuery(query, null);
            if (cursor != null && cursor.getCount() > 0) {
                cursor.moveToFirst();
                do {
                    loc = new GPSLocation();
                    loc.setNumber(cursor.getInt(cursor.getColumnIndex(NUMBER_COLUMN)));
                    loc.setDistance(cursor.getInt(cursor.getColumnIndex(DISTANCE_COLUMN)));
                    loc.setLatitude(cursor.getDouble(cursor.getColumnIndex(LATITUDE_COLUMN)));
                    loc.setLongitude(cursor.getDouble(cursor.getColumnIndex(LATITUDE_COLUMN)));
                } while (cursor.moveToNext());
                db.close();

                Log.d(TAG, "read");
            }
            return loc;
        }
    }

main.xml中：

public class GPSLocation {

    int number, distance;
    double latitude, longitude;

    public GPSLocation(int number, int distance, double latitude, double longitude) {
        this.number = number;
        this.distance = distance;
        this.latitude = latitude;
        this.longitude = longitude;
    }

    public GPSLocation() {
    }

    public int getNumber() {
        return number;
    }

    public void setNumber(int number) {
        this.number = number;
    }

    public int getDistance() {
        return distance;
    }

    public void setDistance(int distance) {
        this.distance = distance;
    }

    public double getLatitude() {
        return latitude;
    }

    public void setLatitude(double latitude) {
        this.latitude = latitude;
    }

    public double getLongitude() {
        return longitude;
    }

    public void setLongitude(double longitude) {
        this.longitude = longitude;
    }
}

数据库：

阅读数据库的输出：

android.database.sqlite.SQLiteException：表XXX没有名为XXX的列（代码1）

1 个答案: