Question

我的数据库有点问题。我在网站上跟随了一个例子，创建了处理数据库所需的一切。不幸的是，它不想工作。我有文本的错误消息：表格gifs没有列名为rating，同时尝试将对象插入该表。我理解这个消息，但我真的不明白为什么一切都应该正常。这是简单的数据库，现在应该添加对象。如果在创建数据库时创建该列，为什么找不到该列？

以下是MAINACTIVITY的代码：

 dataBaseManager.insertGifToDataBase(tmpGif);

其中tmpGif包含字段：名称，日期，评级和网址。除了评级，其余的是字符串。

这是我的SQLiteHelper和Class wchich管理数据库：

public class SqliteHelper extends SQLiteOpenHelper{
public static final String TABLE_NAME = "gifs";
  public static final String NAME = "name";
  public static final String RATING = "rating";
  public static final String DATE = "date";
  public static final String URL = "url";

  private static final String DATABASE_NAME = "gifs.db";
  private static final int DATABASE_VERSION = 1;

  private static final String DATABASE_CREATE = "create table " + TABLE_NAME + "(" + NAME + "text" + "," + RATING + "int" + "," + URL + "text" + "," + DATE + "text" + ");";

public SqliteHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
    //Log.i("DATA BASE", getDatabaseName());
  }

@Override
public void onCreate(SQLiteDatabase database) {

     database.execSQL(DATABASE_CREATE);
}

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

    database.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
    onCreate(database);

}
}

Answer 1

在create table query中缺少列名和数据类型之间的空格以获取正确的结构：

 private static final String DATABASE_CREATE = "create table " + TABLE_NAME + "(" + NAME + "text" + "," + RATING + "int" + "," + URL + "text" + "," + DATE + "text" + ");";

应该是：

 private static final String DATABASE_CREATE = "create table " + TABLE_NAME + "(" + NAME + " text" + "," + RATING + " int" + "," + URL + " text" + "," + DATE + " text" + ");";

因此，表格未正确创建，无法找到列。

Answer 2

您需要在列名称及其类型之间留出空格：

private static final String DATABASE_CREATE = "create table " + TABLE_NAME + "(" + NAME + " text" + "," + RATING + " int" + "," + URL + " text" + "," + DATE + " text" + ");";

所以，例如评分为rating int而不是ratingint。

更新SQL后，卸载您的应用，以便删除旧的数据库文件。

Answer 3

您的DATABASE_CREATE

需要稍作修改

请按以下方式进行

private static final String DATABASE_CREATE = "create table " + TABLE_NAME + "(" + NAME + " text" + "," + RATING + " int" + "," + URL + " text" + "," + DATE + " text" + ");";

数据库Android卡住了

3 个答案: