android - 如何正确初始化游标？

Question

我正在尝试调用数据库查询并访问数据。查询工作正常，并且光标在android device1中移动到了firs，但在android device2中没有。在device2中，它显示此错误

E/CursorWindow: Failed to read row 0, column -1 from a CursorWindow which has 2 rows, 7 columns.
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.stock_design, PID: 25451
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.stock_design/com.example.stock_design.Edit}: java.lang.IllegalStateException: Couldn't read row 0, col -1 from CursorWindow.  Make sure the Cursor is initialized correctly before accessing data from it.
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
    at android.app.ActivityThread.access$900(ActivityThread.java:150)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:148)
    at android.app.ActivityThread.main(ActivityThread.java:5417)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)

这是数据库 Controller 类

val getEdit:List<Item_Edit> get(){
    val db=context.openOrCreateDatabase(REAL_DATABASE, Context.MODE_PRIVATE, null)

    val query ="With cte as (SELECT * FROM Transaction_table ORDER BY (CASE WHEN isbn = '$edt_isbn'  AND location = '$edt_lc' AND branch = '$edt_br'THEN 2 ELSE 1  END), branch) SELECT T.isbn,T.branch,T.location,T.qty,M.article,M.description,M.price FROM cte T LEFT JOIN Master M  WHERE T.isbn = M.isbn"

    val cursor = db.rawQuery(query,null)
    println(edt_isbn)
    if (cursor.moveToFirst()) {

        do {
            seItem.add(Item_Edit(cursor.getString(cursor.getColumnIndex("branch")),
                cursor.getString(cursor.getColumnIndex("location")),
                cursor.getString(cursor.getColumnIndex("isbn")),
                cursor.getString(cursor.getColumnIndex("article")),
                cursor.getString(cursor.getColumnIndex("description")),
                cursor.getString(cursor.getColumnIndex("price")),
                cursor.getString(cursor.getColumnIndex("qty")) ))

        } while(cursor.moveToNext())
    }

    else{
       ck_edt = "false"
    }
    db.close()
    return seItem
}

Answer 1

此错误仅在device2上发生吗？

如果是这样，则错误可能出在该设备的架构中。

failed to read row 0,column -1

表示您正在尝试从不存在的列中进行读取。

检查列名中是否有拼写错误。另外，列名区分大小写，因此也请检查。