Vb.net VB链接SQL server问题
我收到如下错误: 从类型“SqlConnection”到类型“String”的转换无效 我的VB代码是:Vb.net VB链接SQL server问题,vb.net,Vb.net,我收到如下错误: 从类型“SqlConnection”到类型“String”的转换无效 我的VB代码是: Dim conn As New SqlConnection Dim cmd As New SqlCommand Dim da As New SqlDataAdapter Dim dt As New DataTable Dim sSQL As String = String.Empty Try conn = New SqlConn
Dim conn As New SqlConnection
Dim cmd As New SqlCommand
Dim da As New SqlDataAdapter
Dim dt As New DataTable
Dim sSQL As String = String.Empty
Try
conn = New SqlConnection(Get_Constring)
conn.Open()
cmd.Connection = conn
cmd.CommandType = CommandType.Text
sSQL = "SELECT * FROM HostTable"
If Me.cboSearchBy.Text = "Name" Then
sSQL = sSQL & " where HOSTNAME like '%" & Me.txtSearch.Text & "%'"
ElseIf Me.cboSearchBy.Text = "Function" Then
sSQL = sSQL & " where FUCTION like '%" & Me.txtSearch.Text & "%'"
End If
cmd.CommandText = sSQL
da.SelectCommand = cmd
da.Fill(dt)
Me.dtgResult.DataSource = dt
If dt.Rows.Count = 0 Then
MsgBox("No record found!")
End If
Function Get_Constring()
If Microsoft.VisualBasic.Right(Application.StartupPath, 1) = "\" Then
sConnstring = New SqlConnection("server=192.168.1.111\SQLSERVER;database=Common_DB;User ID=sa;Password=12345678")
Else
sConnstring = New SqlConnection("server=192.168.1.111\SQLSERVER;database=Common_DB;User ID=sa;Password=12345678")
End If
Return sConnstring
End Function
从类型“SqlConnection”到类型“String”的转换无效
这个错误信息非常清楚。无法将(新)SqlConnection转换为字符串(sConnstring)。在
新SqlConnection
中硬编码的参数是实际的连接字符串
您可能需要编写类似以下内容:
sConnstring = "server=192.168.1.111\SQLSERVER;database=Common_DB;User ID=sa;Password=12345678"
myConnection = New SqlConnection(sConnstring)
因此,函数Get\u Constring
应该只返回字符串,而不是整个连接
Function Get_Constring()
If Microsoft.VisualBasic.Right(Application.StartupPath, 1) = "\" Then
sConnstring = "server=192.168.1.111\SQLSERVER;database=Common_DB;User ID=sa;Password=12345678"
Else
sConnstring = "server=192.168.1.111\SQLSERVER;database=Common_DB;User ID=sa;Password=12345678"
End If
Return sConnstring
这应该按预期的方式工作。
此外,考虑在Onter选项中严格-强类型地返回和声明变量。或者只需使用Return“server=192.168.1.111\SQLSERVER;database=Common\u DB;User ID=sa;Password=12345678”
并完全省去变量。