需要参数,但未提供该参数的错误

[hulake888]

运行时报错:
被准备语句 '(@title......' 需要参数 @title，但未提供该参数以下是数据层代码:

Dim sql As String = "insert into article(title,content) values (@title,@content)"
Dim conn As SqlConnection = New SqlConnection(constr)

Dim cmd As SqlCommand = New SqlCommand(sql, conn)
Dim sqlparam As SqlParameter

sqlparam = New SqlParameter("@title", SqlDbType.VarChar, 50)
sqlparam.Value = modelarticleinfo.article_title
cmd.Parameters.Add(sqlparam)

请指教,难道modelarticleinfo.article_title取不到数据?

[兔子-顾问]

@content
没看到，你没贴还是没写？

你单步跟踪调试一下看看。

[hulake888]

没有贴

[hulake888]

我怀疑取不到值
把sqlparam.Value = modelarticleinfo.article_title
改成
sqlparam.Value =1
试了一下可以添加数据,但是模板层都没有任何错误,奇怪

[wuyq11]

单步跟踪
完全代码，数据库操作类

[hulake888]

三层架构全部代码：

db层：

Imports System.Data.SqlClient

Public Class db_articleinfo

'Private constr As String = "server=localhost;database=article;uid=sa;pwd="
''' <summary>
''' 插入信息
''' </summary>
''' <param name="modelarticleinfo">一个文章对象</param>
''' <returns>是否添加成功</returns>
''' <remarks>2010-8-23 18:43 by haha</remarks>
Public Function Insert(ByVal modelarticleinfo As model.m_articleinfo) As Boolean
Dim sql As String = "insert into article(title,content) values (@title,@content)"
Dim conn As SqlConnection = New SqlConnection(constr)

Dim cmd As SqlCommand = New SqlCommand(sql, conn)
Dim sqlparam As SqlParameter

sqlparam = New SqlParameter("@title", SqlDbType.VarChar, 50)
sqlparam.Value = modelarticleinfo.article_title
cmd.Parameters.Add(sqlparam)

sqlparam = New SqlParameter("@content", SqlDbType.VarChar, 50)
sqlparam.Value = modelarticleinfo.article_content
cmd.Parameters.Add(sqlparam)

Try
conn.Open()
Return cmd.ExecuteNonQuery() > 0
Catch ex As Exception
MsgBox(Err.Description)
Return False
Finally
If Not IsNothing(conn) Then
conn.Close()
conn = Nothing
End If
End Try

End Function

End Class

bll代码：

Public Class b_articleinfo
Private accessarticleinfo As New accessdb.db_articleinfo
''' <summary>
''' 插入信息
''' </summary>
''' <param name="modelarticleinfo">一个文章对象</param>
''' <returns>是否添加成功</returns>
''' <remarks>2010-8-23 18:43 by haha</remarks>
Public Function insert(ByVal modelarticleinfo As model.m_articleinfo) As Boolean
Return accessarticleinfo.insert(modelarticleinfo)
End Function
End Class



model层：

Public Class m_articleinfo
Private _article_id As Integer
Private _article_title As String
Private _article_content As String

''' <summary>
''' 文章序号
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public Property article_id() As String
Get
Return _article_id
End Get
Set(ByVal value As String)
_article_id = value
End Set
End Property


''' <summary>
''' 文章标题
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public Property article_title() As String
Get
Return _article_title
End Get
Set(ByVal value As String)
_article_content = value
End Set
End Property
''' <summary>
''' 文章内容
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public Property article_content() As String
Get
Return _article_content
End Get
Set(ByVal value As String)
_article_content = value
End Set
End Property

End Class

web层：

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button1.Click
Dim modelarticleinfo As New model.m_articleinfo
Dim bllarticleinfo As New bll.b_articleinfo
modelarticleinfo.article_title = Me.TextBox1.Text
modelarticleinfo.article_content = Me.TextBox2.Text

If bllarticleinfo.insert(modelarticleinfo) Then
Label1.Text = "添加成功"
Else
Label1.Text = "添加失败"
End If

End Sub
End Class

[xiagirl]

''' <summary>
''' 文章标题
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Public Property article_title() As String
Get
Return _article_title
End Get
Set(ByVal value As String)
_article_content = value
End Set
End Property

这里错了啦。

[xiagirl]

要改为 _article_title = value

[hulake888]

谢谢了，出现这么低级的错误，呵呵

[xiagirl]

呵呵。。。。。。。。。。。

[hulake888]

请高手指点

[兔子-顾问]

你调试过么？

[hulake888]

在 System.Data.OleDb.OleDbException 中第一次偶然出现的“System.Data.dll”类型的异常