eclipse - Multiple Markers at this line error, Creating Sqlite Database for Eclipse

Question

当我运行此代码时，会发生错误。我正在尝试创建数据库并通过修改它来学习。我从教程代码中复制了这段代码，它在示例中运行良好，但我无法运行它。你能提供更多关于为什么会发生这种情况的信息吗？

错误是：

此行有多个标记

- The type DatabaseHelper must implement the inherited abstract method SQLiteOpenHelper.onUpgrade(SQLiteDatabase, 
 int, int)
- The public type DatabaseHelper must be defined in its own file
- The type DatabaseHelper must implement the inherited abstract method SQLiteOpenHelper.onCreate(SQLiteDatabase)

我的代码是：

package com.example.eos;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DatabaseHelper extends SQLiteOpenHelper { //ERROR IS HERE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


     static final String dbName="demoDB";
     static final String employeeTable="Employees";
     static final String colID="EmployeeID";
     static final String colName="EmployeeName";
     static final String colAge="Age";
     static final String colDept="Dept";

     static final String deptTable="Dept";
     static final String colDeptID="DeptID";
     static final String colDeptName="DeptName";

     static final String viewEmps="ViewEmps";


    public DatabaseHelper(Context context)
    {
        super(context, dbName, null,33);
    }

}