android - 为什么我的数据库在添加新列后会崩溃？

Question

我正在尝试将一个新列添加到一个中，SQLiteDatabase但每次我尝试使用新列运行代码时它都会崩溃。如果我只是添加新列，那么它运行正常，但是当我尝试在代码中使用它时它会崩溃。有问题的值是KEY_END_TIME任何带有“end”字样的值。我尝试将与相同的确切值传递给它KEY_DATE_TIME，或多或少地在完全相同的上下文中使用它们以试图让它运行，但它每次都会立即崩溃。任何帮助或建议将不胜感激。

/**
 * Simple reminder database access helper class. 
 * Defines the basic CRUD operations (Create, Read, Update, Delete)
 * for the example, and gives the ability to list all reminders as well as
 * retrieve or modify a specific reminder.
 * 
 */
public class RemindersDbAdapter {

//
// Databsae Related Constants
//
private static final String DATABASE_NAME = "data";
private static final String DATABASE_TABLE = "reminders";
private static final int DATABASE_VERSION = 4;

public static final String KEY_TITLE = "title";
public static final String KEY_CUSTOMER = "body";
public static final String KEY_DATE_TIME = "reminder_date_time"; 
public static final String KEY_END_TIME = "reminder_end_time"; 
public static final String KEY_ROWID = "_id";


private static final String TAG = "ReminderDbAdapter";
private DatabaseHelper mDbHelper;
private SQLiteDatabase mDb;

/**
 * Database creation SQL statement
 */
private static final String DATABASE_CREATE =
        "create table " + DATABASE_TABLE + " ("
                + KEY_ROWID + " integer primary key autoincrement, "
                + KEY_TITLE + " text not null, " 
                + KEY_CUSTOMER + " text not null, " 
                + KEY_DATE_TIME + " text not null);"
                + KEY_END_TIME + " text not null);"; 



private final Context mCtx;

private static class DatabaseHelper extends SQLiteOpenHelper {

    DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {

        db.execSQL(DATABASE_CREATE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
                + newVersion + ", which will destroy all old data");

        db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
        onCreate(db);
    }
}

/**
 * Constructor - takes the context to allow the database to be
 * opened/created
 * 
 * @param ctx the Context within which to work
 */
public RemindersDbAdapter(Context ctx) {
    this.mCtx = ctx;
}

/**
 * Open the database. If it cannot be opened, try to create a new
 * instance of the database. If it cannot be created, throw an exception to
 * signal the failure
 * 
 * @return this (self reference, allowing this to be chained in an
 *         initialization call)
 * @throws SQLException if the database could be neither opened or created
 */
public RemindersDbAdapter open() throws SQLException {
    mDbHelper = new DatabaseHelper(mCtx);
    mDb = mDbHelper.getWritableDatabase();
    return this;
}

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


/**
 * Create a new reminder using the title, body and reminder date time provided. 
 * If the reminder is  successfully created return the new rowId
 * for that reminder, otherwise return a -1 to indicate failure.
 * 
 * @param title the title of the reminder
 * @param body the body of the reminder
 * @param reminderDateTime the date and time the reminder should remind the user
 * @return rowId or -1 if failed
 */
public long createReminder(String title, String body, String reminderDateTime, String        reminderEndTime) {
    ContentValues initialValues = new ContentValues();
    initialValues.put(KEY_TITLE, title);
    initialValues.put(KEY_CUSTOMER, body);
    initialValues.put(KEY_DATE_TIME, reminderDateTime);
    initialValues.put(KEY_END_TIME, reminderDateTime); 

    return mDb.insert(DATABASE_TABLE, null, initialValues);
}

/**
 * Delete the reminder with the given rowId
 * 
 * @param rowId id of reminder to delete
 * @return true if deleted, false otherwise
 */
public boolean deleteReminder(long rowId) {

    return mDb.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}

/**
 * Return a Cursor over the list of all reminders in the database
 * 
 * @return Cursor over all reminders
 */
public Cursor fetchAllReminders() {

    return mDb.query(DATABASE_TABLE, new String[] {KEY_ROWID, KEY_TITLE,
            KEY_CUSTOMER, KEY_DATE_TIME, KEY_END_TIME}, null, null, null, null, null);
}

/**
 * Return a Cursor positioned at the reminder that matches the given rowId
 * 
 * @param rowId id of reminder to retrieve
 * @return Cursor positioned to matching reminder, if found
 * @throws SQLException if reminder could not be found/retrieved
 */
public Cursor fetchReminder(long rowId) throws SQLException {

    Cursor mCursor =

            mDb.query(true, DATABASE_TABLE, new String[] {KEY_ROWID,
                    KEY_TITLE, KEY_CUSTOMER, KEY_DATE_TIME, KEY_END_TIME}, KEY_ROWID +     "=" + rowId, null,
                    null, null, null, null);
    if (mCursor != null) {
        mCursor.moveToFirst();
    }
    return mCursor;

}

/**
 * Update the reminder using the details provided. The reminder to be updated is
 * specified using the rowId, and it is altered to use the title, body and reminder     date time
 * values passed in
 * 
 * @param rowId id of reminder to update
 * @param title value to set reminder title to
 * @param body value to set reminder body to
 * @param reminderDateTime value to set the reminder time. 
 * @return true if the reminder was successfully updated, false otherwise
 */
public boolean updateReminder(long rowId, String title, String body, String reminderDateTime, String reminderEndTime) {
    ContentValues args = new ContentValues();
    args.put(KEY_TITLE, title);
    args.put(KEY_CUSTOMER, body);
    args.put(KEY_DATE_TIME, reminderDateTime);
    args.put(KEY_END_TIME, reminderEndTime);

    return mDb.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;
}

}

06-15 18:11:12.356: E/AndroidRuntime(790): FATAL EXCEPTION: main
06-15 18:11:12.356: E/AndroidRuntime(790): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.dummies.android.TaskReminder/com.dummies.android.TaskReminder.TaskReminderActivity}: android.database.sqlite.SQLiteException: no such column: reminder_end_time: , while compiling: SELECT _id, title, body, reminder_date_time, reminder_end_time FROM reminders
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.app.ActivityThread.access$600(ActivityThread.java:123)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.os.Handler.dispatchMessage(Handler.java:99)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.os.Looper.loop(Looper.java:137)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.app.ActivityThread.main(ActivityThread.java:4424)
06-15 18:11:12.356: E/AndroidRuntime(790):  at java.lang.reflect.Method.invokeNative(Native Method)
06-15 18:11:12.356: E/AndroidRuntime(790):  at java.lang.reflect.Method.invoke(Method.java:511)
06-15 18:11:12.356: E/AndroidRuntime(790):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
06-15 18:11:12.356: E/AndroidRuntime(790):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
06-15 18:11:12.356: E/AndroidRuntime(790):  at dalvik.system.NativeStart.main(Native Method)
06-15 18:11:12.356: E/AndroidRuntime(790): Caused by: android.database.sqlite.SQLiteException: no such column: reminder_end_time: , while compiling: SELECT _id, title, body, reminder_date_time, reminder_end_time FROM reminders
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.database.sqlite.SQLiteCompiledSql.native_compile(Native Method)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.database.sqlite.SQLiteCompiledSql.<init>(SQLiteCompiledSql.java:68)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.database.sqlite.SQLiteProgram.compileSql(SQLiteProgram.java:143)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.database.sqlite.SQLiteProgram.compileAndbindAllArgs(SQLiteProgram.java:361)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:127)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:94)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:53)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:47)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1564)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1449)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1405)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1485)
06-15 18:11:12.356: E/AndroidRuntime(790):  at com.dummies.android.TaskReminder.RemindersDbAdapter.fetchAllReminders(RemindersDbAdapter.java:144)
06-15 18:11:12.356: E/AndroidRuntime(790):  at com.dummies.android.TaskReminder.TaskReminderActivity.fillData(TaskReminderActivity.java:40)
06-15 18:11:12.356: E/AndroidRuntime(790):  at com.dummies.android.TaskReminder.TaskReminderActivity.onCreate(TaskReminderActivity.java:33)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.app.Activity.performCreate(Activity.java:4465)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
06-15 18:11:12.356: E/AndroidRuntime(790):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)

score 1 · Accepted Answer

我认为问题在

"create table " + DATABASE_TABLE + " ("
        + KEY_ROWID + " integer primary key autoincrement, "
        + KEY_TITLE + " text not null, " 
        + KEY_CUSTOMER + " text not null, " 
        + KEY_DATE_TIME + " text not null);"
        + KEY_END_TIME + " text not null);";

");" 得到两次

score 1 · Accepted Answer

您的 create 语句格式错误：

 + KEY_DATE_TIME + " text not null);"
            + KEY_END_TIME + " text not null);";

你有关闭“）;” 两次，因此添加 KEY_END_TIME 的行在 create 语句之外并且不被执行。

score 1 · Accepted Answer

您的 sql 创建字符串是错误的。像这样修改它：

...+ KEY_DATE_TIME + " text not null, "
                + KEY_END_TIME + " text not null);";

请记住卸载然后重新安装您的应用程序，以便onCreate再次调用该方法并重新创建数据库。

android - 为什么我的数据库在添加新列后会崩溃？

3 回答 3

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