ASP.NET，VB.NET无法将数据插入SQL Server数据库

Question

I have been troubleshooting this for a week. I try to insert a value into a SQL Server database. It doesn't show any error but when I check the database, there's no data inserted. I might doing something that is wrong here but I can't find it. Thanks for helping.

Dim connect As New SqlConnection(ConfigurationManager.ConnectionStrings("SqlServer").ToString())

Using coa As New SqlCommand()
    With coa
        .Connection = connect
        .CommandType = CommandType.Text
    End With

    Try
       connect.Open()

       Dim insertcmd As String

       insertcmd = "insert into tblUserSection (@newValue, @SectionName, @newSectionID) values ," _
       & "@newValue, @SectionName, @newSectionID);"

       coa.Parameters.Add(New SqlParameter("@newValue", SqlDbType.BigInt))
       coa.Parameters("@newValue").Value = newValue

       coa.Parameters.Add(New SqlParameter("@SectionName", SqlDbType.NVarChar))
       coa.Parameters("@SectionName").Value = SectionName.ToString

       coa.Parameters.Add(New SqlParameter("@newSectionID", SqlDbType.BigInt))
       coa.Parameters("@newSectionID").Value = newSectionID

       coa.ExecuteNonQuery()
       connect.Close()

       MsgBox("success insert")

    Catch ex As Exception
       MsgBox("Fail to Save to database")
    End Try
End Using

Answer 1

The insert command is incorrect. It has parameters for both the column names and the value; the parameter names should only be used for the values.

Assuming the column names match the parameter names, here's an updated version of the command.

insertcmd = "insert into tblUserSection (newValue, SectionName, newSectionID) values ," _
        & "@newValue, @SectionName, @newSectionID);"

The more curious question is why isn't an error showing up. That's because the insert statement is never getting executed. The ExecuteNonQuery command is run against the connection but insertcmd is never associated with the execution in any way.

I'd recommend creating a SQLCommand and using that to execute the query. Here's a sample (and my code might have mistakes, my vb.net is pretty rusty):

Dim sqlcommand as New SqlCommand(coa)
sqlcommand.text = insertcmd
sqlcommand.type = Text
sqlcommand.Parameters.Add(New SqlParameter("@newValue", SqlDbType.BigInt))
sqlcommand.Parameters("@newValue").Value = newValue
sqlcommand.Parameters.Add(New SqlParameter("@SectionName", SqlDbType.NVarChar))
sqlcommand.Parameters("@SectionName").Value = SectionName.ToString
sqlcommand.Parameters.Add(New SqlParameter("@newSectionID", SqlDbType.BigInt))
sqlcommand.Parameters("@newSectionID").Value = newSectionID
sqlcommand.ExecuteNonQuery()

Answer 2

You need to set CommandText property of SqlCommand after creating the insert command string. like:

Dim connect As New SqlConnection(ConfigurationManager.ConnectionStrings("SqlServer").ToString())
    Using coa As New SqlCommand()
        With coa
            .Connection = connect
            .CommandType = CommandType.Text
        End With
        Try
            connect.Open()
            Dim insertcmd As String
            insertcmd = "insert into [TableName] (newValue, SectionName, newSectionID) values " _
            & "(@newValue, @SectionName, @newSectionID);"
            coa.CommandText = insertcmd
            coa.Parameters.Add(New SqlParameter("@newValue", SqlDbType.BigInt))
            coa.Parameters("@newValue").Value = newValue
            coa.Parameters.Add(New SqlParameter("@SectionName", SqlDbType.NVarChar))
            coa.Parameters("@SectionName").Value = SectionName.ToString()
            coa.Parameters.Add(New SqlParameter("@newSectionID", SqlDbType.BigInt))
            coa.Parameters("@newSectionID").Value = newSectionID
            coa.ExecuteNonQuery()
            connect.Close()
            MsgBox("success insert")
        Catch ex As Exception
            MsgBox("Fail to Save to database")
        End Try
    End Using