[VB.NET]100分求助！！！急！！！！！！！！！！！！！！！
发布时间：2020-12-16 23:43:20 所属栏目：大数据 来源：网络整理
导读：100分求助！！！急！！！！！！！！！！！！！！！ 我基本不太会VB，想问些比较简单的问题 我有三个TEXT控件，程序代码中我把它们存成Text(i)数组.下面是我的读取access数据库student表的内容代码，我想根据这三个Text控件的输入来进行查询，为什么不好用呢
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100分求助！！！急！！！！！！！！！！！！！！！ 我基本不太会VB，想问些比较简单的问题 我有三个TEXT控件，程序代码中我把它们存成Text(i)数组.下面是我的读取access数据库student表的内容代码，我想根据这三个Text控件的输入来进行查询，为什么不好用呢，兄弟们帮忙看一下，急死我了啊。！！！ Private Sub Command5_Click() Dim SQLString As String Dim S1 As String,S As String Dim i As Integer For i = 0 To 2 If Text1(i) <> " " Then Select Case i Case 0 S1 = "student.学号 = " & " '' " & Text1(i) & " '' " Case 1 S1 = "student.姓名 = " & " '' " & Text1(i) & " '' " Case 2 S1 = "student.性别 = " & " '' " & Text1(i) & " '' " End Select If S <> " " Then S = S & "AND " & S1 Else S = S1 End If End If Next i SQLString = " SELECT * FROM student WHERE S " Adodc2.RecordSource = SQLString Adodc2.Refresh End Sub 每次我运行时都告诉我至少有一个参数没有指定值，我都快疯了，Adodc指定了connectString,属性中RecordSource 怎么写呢？写select * from student where s 不行吧，S它认识么？所以属性中我都不知道写什么了，还有老提示我的没指定值的问提，大哥们帮帮忙啊，帮我看看我这段程序啊，求求了 __________________________________________________________________________ SQLString = " SELECT * FROM student WHERE S " 改一下再试 SQLString = " SELECT * FROM student WHERE " & S __________________________________________________________________________ S应该等于什么的吧 应该是等于text1的内容 你可以加上= '' " & Text1(i) & " '' 试试 我也是菜鸟 又没做过 access 我做的也都不一样 不过你用的是文本框的话 应该不用写分类事件吧 我用的是combobox 下拉菜单 用了分类可以 仅供参考 __________________________________________________________________________ SQLString = " SELECT * FROM student WHERE " & S __________________________________________________________________________ 先要学会自己调试，你设置一下断点，看看最终拼接成的字符串是否正确？ 另外，尽量不要用拼接的方式组织SQL语句，很容易出错 __________________________________________________________________________ Private Sub Command5_Click() Dim SQLString As String Dim S1 As String,S As String Dim i As Integer For i = 0 To 2 If Text1(i) <> " " Then Select Case i Case 0 S1 = "student.学号 = " & " '' " & Text1(i) & " '' " Case 1 S1 = "student.姓名 = " & " '' " & Text1(i) & " '' " Case 2 S1 = "student.性别 = " & " '' " & Text1(i) & " '' " End Select If S <> " " Then ''AND 前后给空格 S = S & " AND " & S1 Else S = S1 End If End If Next i ''S是变量单独分隔出来 SQLString = " SELECT * FROM student WHERE " & S Adodc2.RecordSource = SQLString Adodc2.Refresh End Sub __________________________________________________________________________ 你这边拼接有问题： If S <> " " Then ''AND 前后给空格 S = S & " AND " & S1 Else S = S1 End If 如果这样拼接的话，最后出来的结果是：SELECT * FROM student WHERE AND student.学号 = XX AND student.姓名 = XX AND student.性别 = XX 建议这样来写： SQLString = " SELECT * FROM student WHERE 1＝1 " & S 在前面这样写： Select Case i Case 0 S1 = " AND student.学号 = " & " '' " & Text1(i) & " '' " Case 1 S1 = " AND student.姓名 = " & " '' " & Text1(i) & " '' " Case 2 S1 = " AND student.性别 = " & " '' " & Text1(i) & " '' " End Select __________________________________________________________________________ 建议这样来写： SQLString = " SELECT * FROM student WHERE 1＝1 " & S 在前面这样写： Select Case i Case 0 S1 = " AND student.学号 = " & " '' " & Text1(i) & " '' " Case 1 S1 = " AND student.姓名 = " & " '' " & Text1(i) & " '' " Case 2 S1 = " AND student.性别 = " & " '' " & Text1(i) & " '' " End Select S = S & S1 __________________________________________________________________________ 大哥们，我按你们的方法都试了，还是不行呀，按你们的方法改完后不提示参数没指定了，但就是点查询按钮没任何反映，ADODC2这个控件右面属性窗口中的RcordSource写什么呢？空么？如果我也写带S的它就又提示我参数没指定值。怎么办啊，我的兄弟们。。。。。 __________________________________________________________________________ Private Sub Command5_Click() Dim SQLString As String Dim S1 As String,S As String Dim i As Integer For i = 0 To 2 If Text1(i) <> " " Then Select Case i Case 0 S1 = " AND student.学号 = " & " '' " & Text1(i) & " '' " Case 1 S1 = " AND student.姓名 = " & " '' " & Text1(i) & " '' " Case 2 S1 = " AND student.性别 = " & " '' " & Text1(i) & " '' " End Select S = S & S1 End If Next i SQLString = " SELECT * FROM student WHERE 1=1 " & S Adodc2.RecordSource = SQLString Adodc2.Refresh End Sub 再试试，如果不行，把断点设在Adodc2.RecordSource = SQLString这上面，把SQLString的值拿到SQL中去查询一下。 __________________________________________________________________________ Private Sub Command5_Click() Dim SQLString As String Dim S1 As String,S As String Dim i As Integer SQLString = "SELECT * FROM student " ''请看下面的SQL写法,假设你有Text1,Text2,Text3 If Not Text1.Text = String.Empty Then SQLString &= " Where " SQLString &= "student.学号 = '' " & Text1.Text & " '' " End If If Not Text2.Text = String.Empty Then If Not Text1.Text = String.Empty Then SQLString &= " And " Else SQLString &= " Where " End If SQLString &= "student.姓名 = '' " & Text2.Text & " '' " End If If Not Text3.Text = String.Empty Then If Not Text1.Text = String.Empty Or Not Text2.Text = String.Empty Then SQLString &= " And " Else SQLString &= " Where " End If SQLString &= "student.性别 = '' " & Text3.Text & " '' " End If Adodc2.RecordSource = SQLString Adodc2.Refresh End Sub __________________________________________________________________________ 我看到了，按你的方法做设置断点调式时我看到的SQL语句的值是select * from student where student.学号= '' 111 ''(我输入111时查询),这里要用trim么，还是数据类型能够不对，怎么读不出来呢？哥们你可以加我QQ么54219484，帮我帮到底吧，兄弟 __________________________________________________________________________ 我这里不能用QQ。 你这样做：表student.学号的类型是什么类型？如果是int的话，不用加‘’的，直接用；如果是string的话，那就要加‘’的，还有要用trim的。 先试试 __________________________________________________________________________ 都是文本类型的，没有INT型的，TRIM我应该怎么样加呢，加在哪？还有ADODC2右面面板上的RcoedSource属性我怎么设置呢，里面也要写SELECT * FROM student WHERE 1=1 & S这个么，还是写什么？ __________________________________________________________________________ DataGrid2的DataSource设为Adodc2。最后可将Adodc2的Visible设为True使之运行时可见。 我是说让你去数据库看看它的类型。 __________________________________________________________________________ Text1.Text.trim __________________________________________________________________________ 我数据库里设计的都是文本类型的，我看了。我问那个ADODC2右面属性里该咋添呢？不是DATAGRID2属性，ADODC2右面属性里有个需要添写SQL语句的地方，添什么呢 __________________________________________________________________________ 在命令文本中输入：select * from student __________________________________________________________________________ 感觉你是在做毕业设计... __________________________________________________________________________ 哥们，问题解决了，有一个控件名写错了，很感谢你对我的帮助，只恨不能给你更多的分，也感谢大家了，我记得的大家，下回我散分给大家 __________________________________________________________________________ （编辑：李大同） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |