Java Android Sqlite数据库错误-无法创建其他表

我知道有很多关于这个问题的帖子，但是我已经尝试了其中的几个，但是当我调用getHomegram方法时仍然会出现这个错误

DatabaseHelper-我认为错误在于以下方法：

public void getHomework() {
SQLiteDatabase localSQLiteDatabase = getReadableDatabase();
String[] tblName  = {};
Cursor localCursor = localSQLiteDatabase.rawQuery("SELECT * FROM homework",tblName);

localCursor.moveToFirst();
while (localCursor.isAfterLast() == false)
{

HashMap<String, String> homework = new HashMap<String, String>();
homework.put("Subject", localCursor.getString(0));
homework.put("DueDate", localCursor.getString(1));
net.attwoodthomas.mytimetable.app.FourthActivity.mHomeworkDue.add(homework);
localCursor.moveToNext();
}


}

public void getLessons()
{
SQLiteDatabase localSQLiteDatabase = getReadableDatabase();
String[] arrayOfString = new String[2];
arrayOfString[0] = MainActivity.mWeek;
arrayOfString[1] = MainActivity.mDay;
Cursor localCursor = localSQLiteDatabase.rawQuery("SELECT Period1, Period2, Period3, Period4, Period5, Period6 FROM lessons WHERE Week = ? AND day = ?", arrayOfString);
Log.d("DatabaseHelper", "1");
localCursor.moveToNext();
Log.d("DatabaseHelper", "2");
net.attwoodthomas.mytimetable.app.SecondActivity.period1 = localCursor.getString(localCursor.getColumnIndex("Period1"));
Log.d("DatabaseHelper", "3");
net.attwoodthomas.mytimetable.app.SecondActivity.period2 = localCursor.getString(localCursor.getColumnIndex("Period2"));
Log.d("DatabaseHelper", "4");
net.attwoodthomas.mytimetable.app.SecondActivity.period3 = localCursor.getString(localCursor.getColumnIndex("Period3"));
Log.d("DatabaseHelper", "5");
net.attwoodthomas.mytimetable.app.SecondActivity.period4 = localCursor.getString(localCursor.getColumnIndex("Period4"));
Log.d("DatabaseHelper", "6");
net.attwoodthomas.mytimetable.app.SecondActivity.period5 = localCursor.getString(localCursor.getColumnIndex("Period5"));
Log.d("DatabaseHelper", "7");
net.attwoodthomas.mytimetable.app.SecondActivity.period6 = localCursor.getString(localCursor.getColumnIndex("Period6"));
Log.d("DatabaseHelper", "8");
localCursor.close();
}

public void onCreate(SQLiteDatabase paramSQLiteDatabase)
{
paramSQLiteDatabase.execSQL("CREATE TABLE lessons (Week VARCHAR(1), Day VARCHAR(10), Period1 VACHAR(20),Period2 VARCHAR(20),Period3 VARCHAR(20),Period4 VARCHAR(20),Period5 VARCHAR(20),Period6 VARCHAR(20));");
paramSQLiteDatabase.execSQL("CREATE TABLE homework (Subject VARCHAR(50), DateDue VARCHAR(50), Description VARCHAR(100));");
if (paramSQLiteDatabase.rawQuery("SELECT * FROM lessons", null).moveToFirst())
{
Log.d("DatabaseHelper", "not emtpy");
return;
}
Log.d("DatabaseHelper", "emtpy");
paramSQLiteDatabase.execSQL("INSERT INTO lessons VALUES ('A', 'Monday', 'PE', 'PE', 'SE', 'Reading', 'Drama', 'Music'), ('A', 'Tuesday', 'PE', 'PE', 'SE', 'Reading', 'Drama', 'Music'),('A', 'Wednesday', 'PE', 'PE', 'SE', 'Reading', 'Drama', 'Music'),('A', 'Thursday', 'PE', 'PE', 'SE', 'Reading', 'Drama', 'Music'),('A', 'Friday', 'PE', 'PE', 'SE', 'Reading', 'Drama', 'Music'),('B', 'Monday', 'PE', 'PE', 'SE', 'Reading', 'Drama', 'Music'),('B', 'Tuesday', 'PE', 'PE', 'SE', 'Reading', 'Drama', 'Music'),('B', 'Wednesday', 'PE', 'PE', 'SE', 'Reading', 'Drama', 'Music'), ('B', 'Thursday', 'PE', 'PE', 'SE', 'Reading', 'Drama', 'Music'),('B', 'Friday', 'PE', 'PE', 'SE', 'Reading', 'Drama', 'Music');");
paramSQLiteDatabase.execSQL("INSERT INTO homework VALUES ('Maths', '08.03.04', 'Finish p38');");
}

public void onUpgrade(SQLiteDatabase paramSQLiteDatabase, int paramInt1, int paramInt2)
{
paramSQLiteDatabase.execSQL("DROP TABLE IF EXISTS CREATE TABLE lessons (Week VARCHAR(1), Day VARCHAR(10), Period1 VACHAR(20),Period2 VARCHAR(20),Period3 VARCHAR(20),Period4 VARCHAR(20),Period5 VARCHAR(20),Period6 VARCHAR(20));");
paramSQLiteDatabase.execSQL("DROP TABLE IF EXISTS CREATE TABLE homework (Subject VARCHAR(50), DateDue VARCHAR(50), Description VARCHAR(100));");
onCreate(paramSQLiteDatabase);
}

整个项目可在github上获得：

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如果我提供的信息太多/太少，我很抱歉。这是我的第一篇帖子。谢谢。更改数据库版本，然后启动应用程序

            OR

二,。尝试卸载应用程序，然后安装

共享日志总是有助于发现代码中的问题…

如果OnUpgrade中存在删除表，则查询不正确

语法是：

DROP TABLE IF EXISTS <DATABASE_NAME>.<TABLE_NAME>

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卸载您的应用程序，使helper onCreate再次运行。更改您的数据库名称，它应该可以工作。请显示完整日志通过使project的新版本感谢更改db版本来修复它，但我遇到了以下错误：android.database.sqlite.SQLiteException:无法将只读数据库从版本0升级到1:有什么想法吗？

DROP TABLE IF EXISTS <DATABASE_NAME>.<TABLE_NAME>