【正文】 寬度 是否允許空 索引 賬號 char 10 F 主鍵 密碼 char 10 F 第四章 系統(tǒng)實現(xiàn)與驗證 16 第四章 系統(tǒng)實現(xiàn)與驗證 系統(tǒng)實現(xiàn) 系統(tǒng)主界面 登錄界面如圖 所示。在 page_load 中添加代碼： (()) 39。加載左側菜單 (()) 39。學生登錄 () (()) 第四章 系統(tǒng)實現(xiàn)與驗證 17 Exit Sub End If If (type) = 1 Then 39。管理登錄 () (()) Exit Sub End If 為一圖片控件， 為用戶登錄 菜單，添加 3 個LinkButton 控件，分學生、教師、管理員身份， 為登錄介紹。在登錄頁面對應的地方輸入用戶名、密碼，確認后登錄。登錄界面如圖 所示。教師、管理員的也相同。登錄界面如圖 所示。 2）退出系統(tǒng)中代碼如下： ()39。 3）修改密碼中代碼如下： If Then () Else Dim db As New dbaccess (Session(type)) (id, Session(user)) (oldpwd, ) (pwd, ) Dim temp As String temp = Session(type) (type, ) (changepwd) If () Then () Else () End If End If 教師模塊功能 教師登陸也同樣傳遞 session 值，將教工號和 type 值保留以備調(diào)用不同的用戶控件。登錄界面如圖 所示。系統(tǒng)還原調(diào)用存儲過程 hy，備份調(diào)用存儲過程 bf，添加、修改、刪除課程信息分別調(diào)用存儲過程 ins_c、 del_c、 course_update， 添加、修改、刪除學生信息分別調(diào)用存儲過程 ins_s、 del_s、 student _update， 添加、修改、刪除課程信息分別調(diào)用存儲過程 ins_t、 del_t、 teacher_update。綁定班級信息 = (0).Columns(1).ToString 39。值為班級號 () 第四章 系統(tǒng)實現(xiàn)與驗證 23 End If submit_Click 中的代碼 If And Then Dim db As New dbaccess (sid, ) (pwd, ) (sname, ) (sex, ) (gradeid, ) (telep, ) (ins_s) If Then = insert success ! Else = insert failure! record may exists ! = = = = = End If Else = 學號或密碼不能為空 ! End If 存儲過程 為了提高效率，使代碼簡單，大量使用了存儲過程。cc39。KILL 39。ok39。 本程序中編寫了一個類，供各摸塊使用，代碼如下： Imports Imports Imports Public Class dbaccess 39。如果返回的第一個表不為空 ,則為 1,反之為 0 Public para As New ListDictionary 39。database= + db + 。pwd=csf) Dim m As New SqlCommand 第四章 系統(tǒng)實現(xiàn)與驗證 26 Dim adp As New SqlDataAdapter(m) = conn = = procNAME () Dim myDE As DictionaryEntry 39。參數(shù)已無用 ,回收空間 If Not (ds Is Nothing) Then 39。如果有結果返回，則為真 End If Else retok = 0 39。 由于本身能力的局限性，所以所編 寫的代碼，即使經(jīng)過反復檢查也難免出錯，所以在本階段力求使用有限的時間找出盡可能多的錯誤，力求系統(tǒng)盡量正確。列舉出幾個驗證過程如表 ， ， ， 所示。加載測試工作貫穿于程序測試工作的全過程，整個錄入、修改、刪除、查詢、處理工作均可視為對數(shù)據(jù)庫的加載測試 工作。 2）主鍵的個數(shù)越少越好。 3）字段的個數(shù)越少越好。數(shù)據(jù)庫的設計中，如何處理多對多的關系和如何設計主鍵，是兩個有著較大難度、需要重點考慮的問題?；緦崿F(xiàn)了學生選課系統(tǒng)所期望的功能，驗證也得到了預期的效果。例如一開始我使用的是框架結構，由于有許多的局限性，又想使用 中的頁面繼承，也沒有得到解決，最后使用 table 和 panel 控件解決了同一頁面鏈接不同的頁面。 在整個設計階段感受最為深刻的是掌握學習的方式和解決問題的方法。 參考文獻 30 參考文獻 [1] 羅斌 . Visual Basic NET 精彩編程實例集錦 .中國水利水電出版社 , [2] 高春蓉 . 與 從入門到精通 .電子工業(yè)出版社 , [3] 楊浩 . 高級編程 .清華大學出版社 , [4] 尚俊杰 . 程序設 計 .清華大學出版社 , [5] 李偉紅 .SQL Server2020 數(shù)據(jù)庫及應用 .中國水利水電出版社 , [6] 龍懷冰 .SQL Server 2020 實用開發(fā)教程 .人民郵電出版社 , [7] Dan Kent . Evolution .Sams , [8] Mahesh Chand, David Talbot .Applied : Building DataDriven Solutions . Apress, [9] John Kauffman, Thiru Thangarathinam .Beginning Databases Beta Preview . Wrox, [10] 李存斌 .SQL Server 2020 實用教程 .中國水利水電出版社 , [11] 劉小偉 . 與 SQL Server 網(wǎng)站開發(fā)實用教程 .電子工業(yè)出版社 , [12] 戴志誠 .SQL Server 2020 數(shù)據(jù)庫系統(tǒng)開發(fā)與實例 .電子工業(yè)出版社 , [13] 賓晟 . 網(wǎng)絡程序開發(fā)原理與實踐教程 .電子工業(yè)出版社 , [14] Thiru Thangarathinam .Professional Databases. wrox, [15] (美 )Joseph ,Paul . SQL Server開發(fā)指南 .電子出版社 , [16] 宋昆 ,李嚴 . SQL Server數(shù)據(jù)庫開發(fā)實例解析 .機械工業(yè)出版社 , [17] 王穎 ,李敏業(yè) . Visual Basic + SQL Server數(shù)據(jù)庫應用實例完全解析 .人民郵電出版社 , [18] 董國平 ,顏志軍 . Visual Basic數(shù)據(jù)庫開發(fā)典型模塊與實例精講 .電子工業(yè)出版社 , 第四章 系統(tǒng)實現(xiàn)與驗證 31 致謝 歷經(jīng)兩個月的努力，在老師的悉心指導下，我們終于順利完成了畢業(yè)設計。從而讓我們對自己有了一個更加準確的認識，對專業(yè)知識有了一個更加融會貫通的理解，更為 下一階段的學習打下了一個重要的基礎。s foot, the sounds died away。 his sword was still in his hand, but it was broken near the hilt。I tried to ta ke the Ring from Frodo 39。I am sorry. I have paid.39。 twenty at least lay there. 39。 He paused and his eyes closed wearily. Afte r a moment he spoke again. 39。 39。 said Aragorn, taking his hand and kissing his brow. 39。 Boromir smiled. 39。 said Aragorn. But Boromir did not speak again. 39。 said Aragorn. 39。s trust in me. What shall I do now? Boromir has laid it on me to go to Minas Tirith, and my heart desires it。 He knelt for a while, bent with weeping, still clasping Boromir39。 and then they stood a moment with heads bowed in grief, for it seemed to them plain what had happened. 39。 said Legolas, ing to Aragorn39。We have hunted and slain many Orcs in the woods, but we should have been of more use here. We came when we heard the hornbut too late, it seems. I fear you have taken deadly hurt.39。Boromir is dead,39。I am unscathed, for I was not here with him. He fell defending the hobbits, while I was awa y upon the hill.39。The hobbits!39。Where are they then? Where is Frodo?39。I do not know,39。Before he died Boromir told me that the Orcs had bound them。 but I did not ask him if Frodo or Sam were with him: not until it was too late. All that I have done today has gone amiss. What is to be done now?39。First we must tend the fallen,39。We cannot leave him lying like carrion among these foul Orcs.39。But we must be swift,39。He would not wish us to linger. We must follow the Orcs, if there is hope that any of our Company are living prisoners.39。But we do not know whether the Ringbearer is with them or not 39。Are we to abandon him? Must we not seek him first? An evil choice is now before us!39。Then let us do first what we must do,39。We have not the time or the tools to bury our rade fitly, or to raise a mound over him. A cairn we might build.39。The labour would be