Check data in Login Form

Check data in Login Form:

Imports System.Data

Imports Oracle.DataAccess.Client 

Imports Oracle.DataAccess.Types

Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        If UsernameTextBox.Text = "" Then

            MsgBox("Please Type UserName")

        ElseIf PasswordTextBox.Text = "" Then

            MsgBox("Please Type Password")

        ElseIf UsernameTextBox.Text = "Admin" And PasswordTextBox.Text = "Admin123" Then

            Form2.Show()

        Else

            Using conn = Opencon()

                Dim cmd As New OracleCommand

                cmd.Connection = conn

                cmd.CommandText = "SELECT USERNAME,PASSWORD FROM LOGINDATA WHERE USERNAME='" & UsernameTextBox.Text & "' AND PASSWORD='" & PasswordTextBox.Text & "'"

                cmd.CommandType = CommandType.Text

                Dim dr As OracleDataReader

                dr = cmd.ExecuteReader()

                If dr.Read() Then

                    UsernameTextBox.Text = dr("USERNAME")

                    PasswordTextBox.Text = dr("PASSWORD")

                    Form2.show()

                Else

                    MsgBox("Please Type Correct UserName and PassWord")

                End If

            End Using

        End If

    End Sub

View Database Data Using Data Grid View

View Database Data Using Data Grid View:

Imports System.Data

Imports Oracle.DataAccess.Client 

Imports Oracle.DataAccess.Types

Using conn = root.Opencon()

                Dim cmd As New OracleCommand

                Dim da1 As New OracleDataAdapter("select * from reg_details", conn)

                Dim table1 As New DataTable()

                da1.Fill(table1)

                DataGridView1.DataSource = New BindingSource(table1, Nothing)

End Using

Edit or Update Data in Database Table

Edit or Update Data in Database Table:

Imports System.Data

Imports Oracle.DataAccess.Client

Imports Oracle.DataAccess.Types

Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click

        If (TextBox1.Text = "") Then

            MsgBox("Please Type RegNo")

       ElseIf (TextBox2.Text = "") Then

            MsgBox("Please Type Name")

        Else

            Using conn = root.Opencon()

                Dim cmd As New OracleCommand

                cmd.Connection = conn

                cmd.CommandText = "SELECT * FROM REG_DETAILS WHERE REGNO='" & TextBox1.Text & "' AND NAME='" & TextBox2.Text & "'"

                cmd.CommandType = CommandType.Text

                Dim drd As OracleDataReader

                drd = cmd.ExecuteReader()

                If drd.Read() Then

                TextBox1.Text = drd("REGNO")

                TextBox2.Text = drd("NAME")

                 MsgBox("Data are Already exsist")

                Else

                    Dim cmd1 As New OracleCommand

                    cmd1.Connection = conn

                    cmd1.CommandText = "UPDATE REG_DETAILS SET REGNO='" & TextBox1.Text & "' AND NAME='" & TextBox2.Text & "'"

                    cmd1.CommandType = CommandType.Text

                    cmd1.ExecuteNonQuery()

                    MsgBox("Record is Successfully Edited")

                End If

            End Using

        End If

    End Sub

Remove Data from Database Table

Remove Data from Database Table:

Imports System.Data

Imports Oracle.DataAccess.Client

Imports Oracle.DataAccess.Types

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

        If (TextBox1.Text = "") Then

            MsgBox("Please Type RegNo")

       ElseIf (TextBox2.Text = "") Then

            MsgBox("Please Type Name")

       Else

            Using conn = root.Opencon()

                Dim cmd As New OracleCommand

                cmd.Connection = conn

                cmd.CommandText = "SELECT * FROM REG_DETAILS WHERE REGNO='" & TextBox1.Text & "' AND NAME='" & TextBox2.Text & "'"

               cmd.CommandType = CommandType.Text

            Dim drd As OracleDataReader

            drd = cmd.ExecuteReader()

            If drd.Read() Then

                TextBox1.Text = drd("REGNO")

                TextBox2.Text = drd("NAME")

                    If Dialog3.ShowDialog() = Windows.Forms.DialogResult.OK Then

                        Dim cmd1 As New OracleCommand

                        cmd1.Connection = conn

                        cmd1.CommandText = "delete from reg_details where REGNO='" & TextBox1.Text & "' AND NAME='" & TextBox2.Text & "'"

                        cmd1.CommandType = CommandType.Text

                        cmd1.ExecuteNonQuery()

                        MsgBox("Record is successfully deleted")

                    ElseIf Dialog3.ShowDialog() = Windows.Forms.DialogResult.Cancel Then

                        Dialog3.Close()

                    End If

                Else

                    MsgBox("Please Type Correct Data to Delete")

                End If

            End Using

         End If

    End Sub

Connection String in Public Function

Connection String in Public Function:

Imports System.Data

Imports Oracle.DataAccess.Client 

Imports Oracle.DataAccess.Types

Public Function Opencon() As OracleConnection

        Dim oradb As String = "Data Source=XE;User Id=HR;Password=password;"

        Dim conn As New OracleConnection(oradb)

        conn.Open()

        Return conn

        conn.Close()

 End Function

Using this function:

 Using conn = Opencon()

...............code......

 End Using