Conversion failed when converting the varchar value 'table' to data type int - asp.net

Question

I'm creating multiple choice question system. So far i create these 4 tables and 1 view.
The tables are tblQuestion, tblAnswer, tblQuiz, tblResult and tblResultDetail. tblQuestion is to store the questions, tblAnswer to store the answers of the question,tblResult is to record for every user that answers the quiz, and store the users answers in TblResultDetails.
Based on the code below, the data is read from view. I use 1 , 2 , 3, 4 as it is the column name of the view. I did this to randomize the answers.
Sub soalan()
conn.Open()
Dim myArr(3) As String
Dim cmd As New SqlCommand("Select * From view_Soalan Where QuestionID=#IdSoalan", conn)
cmd.Parameters.AddWithValue("#IdSoalan", Counter)
Dim dr1 As SqlDataReader
dr1 = cmd.ExecuteReader
If dr1.Read() Then
Me.lblSoalan.Text = dr1("QuestionTxt")
Me.RadioButton1.Text = dr1("1")
myArr(0) = dr1("1")
Me.RadioButton2.Text = dr1("2")
myArr(1) = dr1("2")
Me.RadioButton3.Text = dr1("3")
myArr(2) = dr1("3")
Me.RadioButton4.Text = dr1("4")
myArr(3) = dr1("4")
Dim answerId As String
If Me.RadioButton1.Checked = True Then
answerId = dr1("1")
ElseIf Me.RadioButton2.Checked = True Then
answerId = dr1("2")
ElseIf Me.RadioButton3.Checked = True Then
answerId = dr1("3")
ElseIf Me.RadioButton4.Checked = True Then
answerId = dr1("4")
End If
'Dim jawapan As Integer = CInt(answerId)
Session("jaw") = answerId
Else
conn.Close()
Counter += 1
soalan()
End If
conn.Close()
End Sub
Sub bersih()
RadioButton1.Checked = False
RadioButton2.Checked = False
RadioButton3.Checked = False
RadioButton4.Checked = False
End Sub
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
soalan()
End Sub
Sub masuk()
conn.Open()
Dim cmdGetId As New SqlCommand("Select MAX(ResultId) From TblResult", conn)
cmdGetId.ExecuteNonQuery()
Dim drBaca As SqlDataReader
drBaca = cmdGetId.ExecuteReader
While drBaca.Read
Dim maxID As Integer = drBaca(0)
Session("maximum") = maxID
End While
conn.Close()
conn.Open()
Dim cmdInsert As New SqlCommand("Insert into TblResultDetail (ResultDetail_Result_Id,ResultDetail_Answer_Id) values ('" & Session("maximum") & "','" & Session("jaw") & "')", conn)
cmdInsert.ExecuteNonQuery()
conn.Close()
End Sub
End Class
I got error
Conversion failed when converting the varchar value 'table' to data
type int.
at the cmdInsert command. I know that i cant insert the session("jaw") into table directly. So how to replace it?

Answer 1

In your query you are quoting integers:
... values ('" & Session("maximum") & "','"
Simply remove the quotes. Also you should user Parameters instead to prevent SQL Injection.
I.e.
Dim cmdInsert As New SqlCommand("Insert into TblResultDetail (ResultDetail_Result_Id,ResultDetail_Answer_Id) values (#max, #jaw)", conn)
cmdInsert.Parameters.AddWithValue("#max", Session("maximum"))
cmdInsert.Parameters.AddWithValue("#jaw", Session("jaw"))

Answer 2

I think that you have store in some of this fields a wrong value.
use this
Public Module MyExtensions
<System.Runtime.CompilerServices.Extension()> _
Public Function IsInteger(ByVal value As String) As Boolean
If String.IsNullOrEmpty(value) Then
Return False
Else
Return Integer.TryParse(value, Nothing)
End If
End Function
<System.Runtime.CompilerServices.Extension()> _
Public Function ToInteger(ByVal value As String) As Integer
If value.IsInteger() Then
Return Integer.Parse(value)
Else
Return 0
End If
End Function
End Module
and then
value.ToInteger() <-- returns 0 if it is not an integer
There is another error in your code. You should use ExecuteScalar instead of ExecuteNonQuery in the query that starts with
"Select MAX(ResultId)...."
Dim cmdGetId As New SqlCommand("Select MAX(ResultId) From TblResult", conn)
Dim maxID As Integer= cmdGetId.ExecuteScalar
Session("maximum") = maxID
ExecuteScalar is typically used when your query returns a single value.
ExecuteNonQuery is typically used for SQL statements without results (UPDATE, INSERT, etc.).
Refer this