java - 无法从 CursorWindow 读取第 0 行第 8 列

Question

我遇到了问题。我无法从数据库获取和设置 blob。打开我的应用程序后，我在 Logcat 中收到此错误

Caused by: java.lang.IllegalStateException: Couldn't read row 0, col 8 from CursorWindow. Make sure the Cursor is initialized correctly before accessing data from it.

private static final String KEY_IMAGE = "image";

    public Note getNote(long id){
            SQLiteDatabase db = this.getReadableDatabase();
            Cursor cursor = db.query(DATABASE_TABLE,new String[] {KEY_ID,KEY_TITLE,KEY_CONTENT,KEY_PHONE,KEY_CLIENT,KEY_AGE,KEY_DATE,KEY_TIME,KEY_IMAGE}, KEY_ID+"=?",

                    new String[]{String.valueOf(id)}, null, null,null);
            if (cursor != null)
                cursor.moveToFirst();
            return new Note(cursor.getLong(0)
                    ,cursor.getString(1)
                    ,cursor.getString(2)
                    ,cursor.getString(3)
                    ,cursor.getString(4)
                    ,cursor.getString(5)
                    ,cursor.getString(6)
                    ,cursor.getString(7)
            ,cursor.getBlob(8));
        }

        public List<Note> getNotes() {
            SQLiteDatabase db = this.getReadableDatabase();
            List<Note> allNotes = new ArrayList<>();

            String query = "SELECT * FROM " + DATABASE_TABLE + " ORDER BY "+KEY_TITLE+" ASC";
            Cursor cursor = db.rawQuery(query,null);
            if(cursor.moveToFirst()){
                do{
                    Note note = new Note();
                    note.setID(Long.parseLong(cursor.getString(0)));
                    note.setTitle(cursor.getString(1));
                    note.setAge(cursor.getString(2));
                    note.setPhone(cursor.getString(3));
                    note.setClient(cursor.getString(4));
                    note.setContent(cursor.getString(5));
                    note.setDate(cursor.getString(6));
                    note.setTime(cursor.getString(7));
                    note.setImage(cursor.getBlob(8));
                    allNotes.add(note);


                }while(cursor.moveToNext());

            }

            return allNotes;

        }

感谢您的帮助。

Answer 1

我认为您没有对数据库中访问的数据使用正确的方法，例如，您说 getLong(0) 但该列中可能有其他类型的值，请仔细检查您的创建表查询，如果您想存储图像，您应该使用 fileprovider 而不是 blob。