从SQLite数据库检索数据时出现问题（Android Studio）

我无法从以下代码中检索数据：

该应用程序正在抓取块。应用程序运行到获取块，但当它进入获取块时，它没有响应，模拟器在按下“提交”按钮后没有响应

函数databaseToString位于下面的：

//Print out the database as a string
public String databaseToString() {
    String dbString="";
    mDbHelper = new DBHelper(mCtx);
    SQLiteDatabase db = mDbHelper.getReadableDatabase();
    String query="select * from events where 1";

    //Cursor point to a location in your results
    Cursor c = db.rawQuery(query,null);

    //Move to the first row in your results
    c.moveToFirst();

    while(!c.isAfterLast()){
        if(c.getString(c.getColumnIndex("eventname"))!= null){
            dbString+=c.getString(c.getColumnIndex("eventname"));
            //dbString+=c.getString(c.getColumnIndex("eventdate"));

            dbString+="\n";

        }
    }
    db.close();
    return dbString;
}

---

请从查询中删除

where 1

。现在。此外，在循环的每一步，您都应该

将光标移动到下一条记录
。。！以及如何在每个周期移动光标！不，我没有收到任何错误。。！谢谢你的回复。。！
//Print out the database as a string
public String databaseToString() {
    String dbString="";
    mDbHelper = new DBHelper(mCtx);
    SQLiteDatabase db = mDbHelper.getReadableDatabase();
    String query="select * from events where 1";

    //Cursor point to a location in your results
    Cursor c = db.rawQuery(query,null);

    //Move to the first row in your results
    c.moveToFirst();

    while(!c.isAfterLast()){
        if(c.getString(c.getColumnIndex("eventname"))!= null){
            dbString+=c.getString(c.getColumnIndex("eventname"));
            //dbString+=c.getString(c.getColumnIndex("eventdate"));

            dbString+="\n";

        }
    }
    db.close();
    return dbString;
}