嗨，我得到错误，读取器关闭时无效尝试调用读取。请帮我 [英] Hi I Am Getting Error Like, Invalid Attempt To Call Read When Reader Is Closed. Please Help Me

问题描述

dt = Date.Today

mobj.slct（select * from Books_not_returned where Return_date<'+ dt +'）

while mobj.dr 。阅读

Dim i



Dim a = mobj.dr（0）

Dim b = mobj.dr（1）

Dim c = mobj.dr（2）

Dim d = mobj.dr（3）

Dim f = mobj.dr（4）

g = mobj.dr（5）

h = mobj.dr（6）

i = 5



mobj.execute（更新Books_not_returned set fine ='+ i.ToString +'其中Member_ID ='+ a.ToString +'和Book_ID ='+ c.ToString +'）

结束时

dt = Date.Today
mobj.slct("select * from Books_not_returned where Return_date <'" + dt + "'")
While mobj.dr.Read
Dim i

Dim a = mobj.dr(0)
Dim b = mobj.dr(1)
Dim c = mobj.dr(2)
Dim d = mobj.dr(3)
Dim f = mobj.dr(4)
g = mobj.dr(5)
h = mobj.dr(6)
i = 5

mobj.execute("update Books_not_returned set fine ='" + i.ToString + "' where Member_ID='" + a.ToString + "' and Book_ID='" + c.ToString + "'")
End While

推荐答案

参考：使用DataReader检索数据 [ ^ ]

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