Question

我通过定义如下来创建数据库表： -

public static final String Create_Database2= "CREATE TABLE " + Table_Name2 + "("
                + play20 + " INTEGER PRIMARY KEY, "
                + play1 + " LONG, " 
                + play2 + " LONG, " 
                + play3 + " INTEGER, " 
                + play4 + " INTEGER, " 
                + play5 + " LONG, " 
                + play6 + " TEXT, " 
                + play7 + " TEXT, " 
                + play8 + " TEXT, " 
                + play9 + " TEXT, " 
                + play10 + " TEXT, " 
                + play11 + " INTEGER, " 
                + play12 + " INTEGER, " 
                + play13 + " INTEGER, " 
                + play14 + " INTEGER, " 
                + play15 + " INTEGER, " 
                + play16 + " INTEGER, " 
                + play17 + " TEXT, " 
                + play18 + " INTEGER, " 
                + play19 + " TEXT"
                + ") ";

现在我从中获取数据： -

 public Cursor getcontent()
       {
           Cursor d= database.query(DatabaseHandler.Table_Name2,allColumns,selection, null, null,null,null); 
      }
 public String[] allColumns = { DatabaseHandler.play5, DatabaseHandler.play6,DatabaseHandler.play7,
            DatabaseHandler.play8,DatabaseHandler.play9,DatabaseHandler.play10 };
String selection="playlist_id=100813";

以上是我的数据选择标准

 Cursor r=X.getcontent();
             if (r.getCount() > 0) {
             r.moveToFirst();
                do {
                 String id = r.getString(r.getColumnIndex("content_id"));
                      al.add(id);
                     String from_date =r.getString(r.getColumnIndex("from_date"));
                   String to_date =r.getString(r.getColumnIndex("to_date"));
                   String from_time =r.getString(r.getColumnIndex("from_time"));
                   String to_time =r.getString(r.getColumnIndex("to_time"));
                   String days =r.getString(r.getColumnIndex("days"));
                    String duration =r.getString(r.getColumnIndex("duration"));
                } while (r.moveToNext()==true);
               r.close();
                } else {
               Log.i("TAG"," No value found");
           }

我在logcat中收到此错误

02-22 15:37:04.565: E/AndroidRuntime(11544): FATAL EXCEPTION: main
02-22 15:37:04.565: E/AndroidRuntime(11544): java.lang.RuntimeException: 
Unable to start activity ComponentInfo{com.example.webdata/com.example.webdata.MainActivity}:java.lang.IllegalStateException:
Couldnt read row 0, col -1 from CursorWindow.  Make sure the Cursor is initialized correctly before accessing data from it.

我在这里做错了什么？

Answer 1

检查条件if（r.moveToFirst（））前进

光标未正确初始化？

1 个答案: