SQLite:表X没有名为Y的列

Question

我在这里已经阅读了很多关于上述问题的线索/问题,但似乎没有任何解决方案对我有用.这是我的数据库创建:

  public static final String TABLE_CARDS = "cards";
  public static final String COLUMN_ID = "_id";
  public static final String COLUMN_QUESTION = "question";
  public static final String COLUMN_ANSWER = "answer";

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

  // Database creation sql statement
  private static final String DATABASE_CREATE = "create table "
      + TABLE_CARDS + "(" 
      + COLUMN_ID + " integer primary key autoincrement, " 
      + COLUMN_QUESTION + " text not null, " 
      + COLUMN_ANSWER + " text not null);";

在这里,我将一个新对象传递给数据库:

 public Card createCard(String question, String answer) {
    ContentValues values = new ContentValues();
    values.put(MySQLiteHelper.COLUMN_QUESTION, question);
    values.put(MySQLiteHelper.COLUMN_ANSWER, answer);

    long insertId = database.insert(MySQLiteHelper.TABLE_CARDS, null,
        values); 

    Cursor cursor = database.query(MySQLiteHelper.TABLE_CARDS,
        allColumns, MySQLiteHelper.COLUMN_ID + " = " + insertId, null,
        null, null, null);
    cursor.moveToFirst();


    Card newCard = cursorToCard(cursor);
    cursor.close();
    return newCard;
  }

编辑:

错误消息:

10-12 07:07:55.503: E/SQLiteDatabase(796): Error inserting answer=testanw question=testqu
10-12 07:07:55.503: E/SQLiteDatabase(796): android.database.sqlite.SQLiteException: table cards has no column named answer (code 1): , while compiling: INSERT INTO cards(answer,question) VALUES (?,?)
10-12 07:07:55.503: E/SQLiteDatabase(796):  at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
10-12 07:07:55.503: E/SQLiteDatabase(796):  at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:889)
10-12 07:07:55.503: E/SQLiteDatabase(796):  at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:500)
10-12 07:07:55.503: E/SQLiteDatabase(796):  at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
10-12 07:07:55.503: E/SQLiteDatabase(796):  at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
10-12 07:07:55.503: E/SQLiteDatabase(796):  at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31)
10-12 07:07:55.503: E/SQLiteDatabase(796):  at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1467)

问题是,只要我想写入数据库,就会抛出此错误.我想在我的卡片数据库中存储一个名为问题和答案的字符串.很抱歉错过这些信息!!

Answer 1

卸载您的应用并重新安装.您之前可能已创建此表,并且该列在早期版本的应用程序中不存在.

添加列并且不使用onUpdate方法时,现有表不会添加新列.这并不是说您应该onUpdate在开发期间每次更改架构时onUpdate使用 - 应该在实际发布应用程序的新版本时使用.