SQLite：表X没有列名为Y

Question

我已阅读了很多关于上述问题的线程/问题，但没有解决方案似乎对我有用。这里是我的数据库创建：

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，我传递一个新的对象到数据库：

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) 

而且问题只要我想写入数据库就会抛出这个错误。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。对不起，错过了这些信息！

Answer 1

卸载您的应用程序并重新安装。您可能以前创建过此表，并且此列在您的应用的早期版本中不存在。

当您添加一列而不使用onUpdate方法时，现有表格不会添加新列。这并不是说每次在开发过程中更改架构时都应该使用onUpdate-当您实际发布应用的新版本时应使用onUpdate。

Answer 2

当您不使用onUpdate（）方法时，只要在表中添加新列时每次都更改数据库的名称。