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Imports System.Data.OleDb
Imports System.String
' Form Load
Public Class StudInfos
    Private Sub StudInfos_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        CurrentRow = 0
        Con.Open()
        Dad = New OleDbDataAdapter("SELECT * FROM Students ORDER BY NickName", Con)
        Dad.Fill(Dst, "StudsInfo")
        ShowData(CurrentRow)
        Con.Close()
    End Sub
    ' To display data on form
    Private Sub ShowData(ByVal CurrentRow)
        Try
            txtNick.Text = Dst.Tables("StudsInfo").Rows(CurrentRow)("NickName")
            txtFirst.Text = Dst.Tables("StudsInfo").Rows(CurrentRow)("FirstName")
            txtLast.Text = Dst.Tables("StudsInfo").Rows(CurrentRow)("LastName")
            txtAge.Text = Dst.Tables("StudsInfo").Rows(CurrentRow)("Age")
            txtGender.Text = Dst.Tables("StudsInfo").Rows(CurrentRow)("Gender")
            txtAddress.Text = Dst.Tables("StudsInfo").Rows(CurrentRow)("Address")
            txtContact.Text = Dst.Tables("StudsInfo").Rows(CurrentRow)("ContactNo")
        Catch ex As Exception
        End Try
    End Sub

    'To select the data in NickName field
    Private Sub Nick_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtNick.GotFocus
        txtNick.SelectAll()
    End Sub

    ' To insert the record in database
    Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click

        Dim Str As String
        Try
            Str = "insert into Students values("
            Str += txtNick.Text.Trim()
            Str += ","
            Str += """" & txtFirst.Text.Trim() & """"
            Str += ","
            Str += """" & txtLast.Text.Trim() & """"
            Str += ","
            Str += """" & txtAge.Text.Trim() & """"
            Str += ","
            Str += """" & txtGender.Text.Trim() & """"
            Str += ","
            Str += """" & txtAddress.Text.Trim() & """"
            Str += ","
            Str += txtContact.Text.Trim()
            Str += ")"
            Con.Open()
            Cmd = New OleDbCommand(Str, Con)
            Cmd.ExecuteNonQuery()
            Dst.Clear()
            Dad = New OleDbDataAdapter("SELECT * FROM Students ORDER BY NickName", Con)
            Dad.Fill(Dst, "StudsInfo")
            MsgBox("Record inserted successfully...")
            Con.Close()
        Catch ex As Exception
            MessageBox.Show("Could Not Insert Record!!!")
            MsgBox(ex.Message & " -  " & ex.Source)
            Con.Close()
        End Try
    End Sub
    ' To delete the record from database
    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDelete.Click
        Dim Str As String
        If CheckNickName() = False Then
            MsgBox("NickName : Integer Value Required!!!")
            Exit Sub
        End If
        Try
            Str = "DELETE from Students where NickName="
            Str += txtNick.Text.Trim
            Con.Open()
            Cmd = New OleDbCommand(Str, Con)
            Cmd.ExecuteNonQuery()
            Dst.clear()
            Dad = New OleDbDataAdapter("SELECT * FROM StudsInfo ORDER BY NickName", Con)
            Dad.Fill(Dst, "StudsInfo")
            MsgBox("Record deleted successfully...")
            If CurrentRow > 0 Then
                CurrentRow -= 1
                ShowData(CurrentRow)
            End If
            Con.Close()
        Catch ex As Exception
            MessageBox.Show("Could Not delete Record!!!")
            MsgBox(ex.Message & " -  " & ex.Source)
        End Try
        Con.Close()
    End Sub
    ' To select the data in First Name Field
    Private Sub FName_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtLast.GotFocus
        txtFirst.SelectAll()
    End Sub
    ' To select the data in Last Name Field
    Private Sub LName_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtFirst.GotFocus
        txtLast.SelectAll()
    End Sub
    ' To select the data in Designation Field
    Private Sub Designation_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtAddress.GotFocus
        txtAddress.SelectAll()
    End Sub
    ' To select the data in Salary Field
    Private Sub Salary_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs)
        txtAge.SelectAll()
    End Sub
    Private Sub Names_keypress(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtAddress.KeyPress, txtAge.KeyPress, txtContact.KeyPress, txtFirst.KeyPress, txtGender.KeyPress, txtLast.KeyPress, txtNick.KeyPress
        If CheckNickName() = False Then
            MsgBox("NickName : Integer Value Required !!!")
            Exit Sub
        ElseIf CheckFName() = False Then
            MsgBox("FName : Only Characters Allowed!!!")
            Exit Sub
        ElseIf CheckLName() = False Then
            MsgBox("LName : Only Characters Allowed!!!")
            Exit Sub
        ElseIf CheckAge() = False Then
            MsgBox("age : Integer Value Required !!!")
            Exit Sub
        ElseIf CheckGender() = False Then
            MsgBox("gender : Integer  Allowed!!!")
            Exit Sub
        ElseIf CheckAddress() = False Then
            MsgBox("Address : Only Characters Allowed!!!")
            Exit Sub
        ElseIf CheckContactNo() = False Then
            MsgBox("contactno : Integer  Allowed!!!")
            Exit Sub
        End If
    End Sub
    ' To update the records in database
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click

        Try
            Dim Str As String
            Str = "Update Students set NickName="
            Str += """" & txtNick.Text & """"
            Str += " where NickName="
            Str += txtNick.Text.Trim()
            Con.Open()
            Cmd = New OleDbCommand(Str, Con)
            Cmd.ExecuteNonQuery()
            Con.Close()

            Con.Open()
            Str = "update StudsInfo set FirstName="
            Str += """" & txtFirst.Text & """"
            Str += " where NickName="
            Str += txtNick.Text.Trim()
            Cmd = New OleDbCommand(Str, Con)
            Cmd.ExecuteNonQuery()
            Con.Close()

            Con.Open()
            Str = "update Students set LastName="
            Str += """" & txtLast.Text & """"
            Str += " where NickName="
            Str += txtNick.Text.Trim()
            Cmd = New OleDbCommand(Str, Con)
            Cmd.ExecuteNonQuery()
            Con.Close()

            Con.Open()
            Str = "update StudsInfo set Age="
            Str += """" & txtAge.Text & """"
            Str += " where NickName="
            Str += txtNick.Text.Trim()
            Cmd = New OleDbCommand(Str, Con)
            Cmd.ExecuteNonQuery()
            Con.Close()

            Con.Open()
            Str = "update StudsInfo set Gender="
            Str += """" & txtGender.Text & """"
            Str += " where NickName="
            Str += txtNick.Text.Trim()
            Cmd = New OleDbCommand(Str, Con)
            Cmd.ExecuteNonQuery()
            Con.Close()

            Con.Open()
            Str = "update StudsInfo set Address="
            Str += """" & txtAddress.Text & """"
            Str += " where NickName="
            Str += txtNick.Text.Trim()
            Cmd = New OleDbCommand(Str, Con)
            Cmd.ExecuteNonQuery()
            Con.Close()


            Con.Open()
            Str = "update StudsInfos set ContactNo="
            Str += """" & txtContact.Text & """"
            Str += " where NickName="
            Str += txtNick.Text.Trim()
            Cmd = New OleDbCommand(Str, Con)
            Cmd.ExecuteNonQuery()
            Con.Close()


            Dst.Clear()
            Dad = New OleDbDataAdapter("SELECT * FROM Students ORDER BY NickName", Con)
            Dad.Fill(Dst, "StudsInfo")
            MsgBox("Updated Successfully...")
        Catch ex As Exception
            MsgBox(ex.Message & "," & ex.Source)
        End Try
    End Sub
    ' To Navigate to First Record
    Private Sub First_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles First.Click
        CurrentRow = 0
        ShowData(CurrentRow)
    End Sub
    ' To Navigate to Last Record
    Private Sub Previous_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Previous.Click
        If CurrentRow <> 0 Then
            CurrentRow -= 1
            ShowData(CurrentRow)
        Else
            MsgBox("First Record is Reached!!!")
        End If
    End Sub
    ' To Navigate to Next Record
    Private Sub Forward_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Forward.Click
        If CurrentRow = Dst.Tables("StudsInfo").Rows.Count - 1 Then
            MsgBox("Last Record is Reached!!!")
        Else
            CurrentRow += 1
            ShowData(CurrentRow)
        End If
    End Sub
    ' To Navigate to Last Record
    Private Sub Last_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Last.Click
        CurrentRow = Dst.Tables("StudsInfo").Rows.Count - 1
        ShowData(CurrentRow)
    End Sub
    ' To check the data in NickName field : whether String or not 
    Private Function CheckNickName()
        Try
            If txtNick.Text = "" Or ValNickNameateString(txtNick.Text) = False Then
                ShowData(CurrentRow)
                txtNick.Focus()
                Return False
            End If
        Catch ex As Exception
        End Try
        Return True
    End Function

    ' To check the data in Age field : whether numeric or not 
    Private Function CheckAge()
        Try
            If IsNumeric(txtAge.Text) = False Then
                ShowData(CurrentRow)
                txtAge.Focus()
                Return False
            End If
        Catch ex As Exception
        End Try
        Return True
    End Function
    ' To check the data in Contactno field : whether numeric or not 
    Private Function CheckContactNo()
        Try
            If IsNumeric(txtContact.Text) = False Then
                ShowData(CurrentRow)
                txtContact.Focus()
                Return False
            End If
        Catch ex As Exception
        End Try
        Return True
    End Function

    ' To check the data in First Name Field : whether a string or not

    Private Function CheckFName()
        Try
            If txtFirst.Text = "" Or ValNickNameateString(txtFirst.Text) = False Then
                ShowData(CurrentRow)
                txtFirst.Focus()
                Return False
            End If
        Catch ex As Exception
        End Try
        Return True
    End Function
    ' To check the data in Last Name Field : whether a string or not
    Private Function CheckLName()
        Try
            If txtLast.Text = "" Or ValNickNameateString(txtLast.Text) = False Then
                ShowData(CurrentRow)
                txtLast.Focus()
                Return False
            End If
        Catch ex As Exception
        End Try
        Return True
    End Function
    ' To check the data in address Field : whether a string or not
    Private Function CheckAddress()
        Try
            If txtAddress.Text = "" Or ValNickNameateString(txtAddress.Text) = False Then
                ShowData(CurrentRow)
                txtAddress.Focus()
                Return False
            End If
        Catch ex As Exception
        End Try
        Return True
    End Function
    Private Function CheckGender()
        Try
            If txtGender.Text = "" Or ValNickNameateString(txtGender.Text) = False Then
                ShowData(CurrentRow)
                txtGender.Focus()
                Return False
            End If
        Catch ex As Exception
        End Try
        Return True
    End Function
    ' To check the string for numeric values
    Private Function ValNickNameateString(ByVal Str)
        Dim i As Integer
        Dim ch As Char
        i = 0
        While i < Str.Length()
            ch = Str.Chars(i)
            If IsNumeric(ch) = True Then
                Return False
            End If
            i += 1
        End While
        Return True
    End Function

    ' To check whether NickName exist in database
    Private Function IsNickNameExist()
        Dim Str, Str1 As String
        Dim i As Integer
        Str = txtNick.Text
        i = 0
        While i <> Dst.Tables("StudsInfo").rows.count
            Str1 = Dst.Tables("StudsInfo").Rows(i)("NickName")
            If Str = Str1 Then
                Return True
            End If
            i += 1
        End While
        Return False
    End Function

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        ViewStudents.Show()
    End Sub

    Private Sub btnClear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClear.Click
        ' To clear all fields : NickName, First Name, Last Name
        txtNick.Text = ""
        txtFirst.Text = ""
        txtLast.Text = ""
        txtAge.Text = ""
        txtAddress.Text = ""
        txtGender.Text = ""
        txtContact.Text = ""
    End Sub
End Class