Check if Row is already exist in table before inserting - vb.net

Question

Well its been a while since my last post about saving loops through checkboxlist.So I did manage to check the input before it saved into table, but somehow it couldnt save any data even if wasnt duplicate one.
Wanted to create a function to check if each checkboxlist is already present within the table but I cant manage it because it needs value from this script so I skip it.
Using conn2 As New SqlConnection()
conn2.ConnectionString = ConfigurationManager _
.ConnectionStrings("BackboneConnectionString").ConnectionString()
Using cmd As New SqlCommand
cmd.CommandText = "Insert into EL_MstFunctionalNilai values(#IDFunc, #nik, #IDFuncParent, #IDFuncChild, #IDFuncMtr, '', '', '0')"
cmd.Connection = conn2
conn2.Open()
For Each item As ListItem In CheckBoxList2.Items
If item.Selected Then
'cmd.Parameters.Clear()
Dim urutan As Int32 = GetNumberFunctional()
Dim str As String = item.Value.ToString
Dim strArr() As String = str.Split("_")
Dim IDFunctionalParent1 As String = strArr(0)
Dim IDFunctionalChild1 As String = strArr(1)
Dim IDFunctionalMtr1 As String = strArr(2)
cmd.CommandText = "select count(*)as numrows from el_mstFunctionalnilai where nik = #nik and idfuncmtr = #IDFuncMtr"
cmd.Parameters.AddWithValue("#nik", txtnik.Text)
cmd.Parameters.AddWithValue("#IDFuncMtr", IDFunctionalMtr1)
queryresult = cmd.ExecuteScalar()
If queryresult = 0 Then
cmd.Parameters.Clear()
cmd.Parameters.AddWithValue("#IDFunc", urutan)
cmd.Parameters.AddWithValue("#nik", txtnik.Text)
cmd.Parameters.AddWithValue("#IDFuncMtr", IDFunctionalMtr1) 'mtr
cmd.Parameters.AddWithValue("#IDFuncParent", IDFunctionalParent1) 'parent
cmd.Parameters.AddWithValue("#IDFuncChild", IDFunctionalChild1) 'child
cmd.ExecuteNonQuery()
'Label1.Text = queryresult --> already check if queryresult has value
End If
End If
Next
conn2.Close()
End Using
End Using
When its executed no error tho, so I cant figure it out what Im missing. Well how do I fix this up?
Thanks.

Answer 1

el_mstFunctionalnilai
EL_MstFunctionalNilai
Which is it? Be careful about capitalization.
I have guessed at all the SqlDbType Please check your database to get the actual types.
Code following your pattern with 2 hits to database.
Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim queryResult As Integer
'Pass the connection string directly to the constructor of the connection
Using conn2 As New SqlConnection(ConfigurationManager.ConnectionStrings("BackboneConnectionString").ConnectionString())
'Pass the command text and the connection directly to the command constructor
'You do not need as alias for Count
Using cmd As New SqlCommand("select count(*) from EL_MstFunctionalNilai where nik = #nik and idfuncmtr = #IDFuncMtr", conn2)
conn2.Open()
'This value does not appear to change in the loop so I moved it outside the loop
Dim urutan As Int32 = GetNumberFunctional()
'Add the parameters outside of the loop and only change the value inside the loop
'The value of the text box can't change inside the loop so it can be assigned outside the loop
cmd.Parameters.Add("#nick", SqlDbType.Int).Value = CInt(txtnik.Text)
cmd.Parameters.Add("#IDFuncMtr", SqlDbType.VarChar)
Using cmd2 As New SqlCommand("Insert into EL_MstFunctionalNilai values(#IDFunc, #nik, #IDFuncParent, #IDFuncChild, #IDFuncMtr, '', '', '0')", conn2)
cmd2.Parameters.Add("#IDFunc", SqlDbType.Int).Value = urutan
cmd2.Parameters.Add("#nik", SqlDbType.Int).Value = CInt(txtnik.Text)
cmd2.Parameters.Add("#IDFuncMtr", SqlDbType.VarChar) 'mtr
cmd2.Parameters.Add("#IDFuncParent", SqlDbType.VarChar) 'parent
cmd2.Parameters.Add("#IDFuncChild", SqlDbType.VarChar) 'child
For Each item As ListItem In CheckBoxList2.Items
If item.Selected Then
Dim str As String = item.Value.ToString
Dim strArr() As String = str.Split("_"c)
Dim IDFunctionalParent1 As String = strArr(0)
Dim IDFunctionalChild1 As String = strArr(1)
Dim IDFunctionalMtr1 As String = strArr(2)
cmd.Parameters("#IDFuncMtr").Value = IDFunctionalMtr1
queryResult = CInt(cmd.ExecuteScalar())
If queryResult = 0 Then
cmd2.Parameters("#IDFuncMtr").Value = IDFunctionalMtr1 'mtr
cmd2.Parameters("#IDFuncParent").Value = IDFunctionalParent1 'parent
cmd2.Parameters("#IDFuncChild").Value = IDFunctionalChild1 'child
cmd.ExecuteNonQuery()
End If
End If
Next
End Using
End Using
End Using
End Sub
I think it would be easier using one query that both checks for the existence of the record and inserts it if it doesn't exist.
Protected Sub Method2()
Dim urutan As Int32 = GetNumberFunctional()
Using cn As New SqlConnection(ConfigurationManager.ConnectionStrings("BackboneConnectionString").ConnectionString())
Using cmd As New SqlCommand("If Exists (Select 1 From EL_MstFunctionalNilai where nik = #nik and idfuncmtr = #IDFuncMtr) Select 0 Else Select 1 Insert into EL_MstFunctionalNilai values(#IDFunc, #nik, #IDFuncParent, #IDFuncChild, #IDFuncMtr, '', '', '0');", cn)
cmd.Parameters.Add("#nik", SqlDbType.Int).Value = CInt(txtnik.Text)
cmd.Parameters.Add("#IDFuncMtr", SqlDbType.VarChar)
cmd.Parameters.Add("#IDFunc", SqlDbType.VarChar).Value = urutan
cmd.Parameters.Add("#IDFuncParent", SqlDbType.VarChar)
cmd.Parameters.Add("#IDFuncChild", SqlDbType.VarChar)
cn.Open()
For Each item As ListItem In CheckBoxList2.Items
If item.Selected Then
Dim strArr() As String = item.Value.ToString.Split("_"c)
cmd.Parameters("#IDFuncMtr").Value = strArr(2)
cmd.Parameters("#IDFuncParent").Value = strArr(0)
cmd.Parameters("#IDFuncChild").Value = strArr(1)
cmd.ExecuteScalar()
End If
Next
End Using
End Using
End Sub