Visual Basic.net: get duplicate records in SQL Server[ with source code ]

 

Imports System.Data.SqlClient

Public Class Form1

    Dim conn As New SqlConnection("Data Source=.;Initial Catalog=Names;Integrated Security=True")

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        If conn.State = ConnectionState.Closed Then

            conn.Open()

        End If

        Dim cmd1 As New SqlCommand("select * from table1 where name In (Select name from table1 Group by name having (Count(*)>1)) order by name", conn)

        Dim da As New SqlDataAdapter

        Dim dt As New DataTable

        da.SelectCommand = cmd1

        dt.Clear()

        da.Fill(dt)

        DataGridView1.DataSource = dt

        conn.Close()

    End Sub

End Class

C# : Create Login form in C# step by step [ with source code ]

 

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.Data.SqlClient;

namespace login

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)

        {

            SqlConnection conn = new SqlConnection("Data source=.; initial catalog=users;integrated security=true");

            SqlCommand cmd = new SqlCommand("select * from login1 where user1=@user1 and pass1=@pass1", conn);

            cmd.Parameters.Add("@user1", SqlDbType.VarChar).Value = textBox1.Text;

            cmd.Parameters.Add("@pass1", SqlDbType.VarChar).Value = textBox2.Text;

            SqlDataAdapter adapter1 = new SqlDataAdapter(cmd);

            DataTable table = new DataTable();

            adapter1.Fill(table);

            if (table.Rows.Count == 1)

            {

                Form2 gg = new Form2();

                gg.Show();

                this.Hide();

            }

            else

            {

                MessageBox.Show("Error username or password");

            }

        }

        private void button2_Click(object sender, EventArgs e)

        {

            this.Close();

        }

        private void checkBox1_CheckedChanged(object sender, EventArgs e)

        {

            if (checkBox1.Checked == true)

            {

                textBox2.UseSystemPasswordChar = false;

            }

            else

            {

                textBox2.UseSystemPasswordChar = true;

            }

        }

    }

    }

Visual basic.net: search data on datagridview using Textbox value by event TextChanged[ with code ]

 

Imports System.Data.OleDb

Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub

    Private Sub TextBox1_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged

        Dim conn As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E:\ddd.accdb")

      

        If conn.State = ConnectionState.Closed Then

            conn.Open()

        End If

        Dim cmd1 As New OleDbCommand("select id,firstname,lastname,sum from table1 where firstname like '%" + TextBox1.Text + "%'", conn)

        Dim da As New OleDbDataAdapter

        Dim dt As New DataTable

        da.SelectCommand = cmd1

        dt.Clear()

        da.Fill(dt)

        DataGridView1.DataSource = dt

        

        conn.Close()

    End Sub

End Class

Connect SQL server database with Visual Studio C# [ with source code ]

 

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

namespace WindowsFormsApplication1

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void Form1_Load(object sender, EventArgs e)

        {

            // TODO: This line of code loads data into the 'names1DataSet.Table1' table. You can move, or remove it, as needed.

            this.table1TableAdapter.Fill(this.names1DataSet.Table1);

            

        }

        private void button1_Click(object sender, EventArgs e)

        {

            table1BindingSource.AddNew();

        }

        private void button2_Click(object sender, EventArgs e)

        {

            table1BindingSource.EndEdit();

            table1TableAdapter.Update(names1DataSet.Table1);

        }

        private void button3_Click(object sender, EventArgs e)

        {

            table1BindingSource.RemoveCurrent();

    table1TableAdapter.Update(names1DataSet.Table1);

        }

        private void button4_Click(object sender, EventArgs e)

        {

            this.Close();

        }

        private void button5_Click(object sender, EventArgs e)

        {

            table1BindingSource.MoveFirst();

        }

        private void button6_Click(object sender, EventArgs e)

        {

            table1BindingSource.MoveLast();

        }

        private void button7_Click(object sender, EventArgs e)

        {

            table1BindingSource.MovePrevious();

        }

        private void button8_Click(object sender, EventArgs e)

        {

            table1BindingSource.MoveNext();

        }

    }

}

Find Duplicates From a Table in SQL Server

 

Select id,name,tel from table1

where name In (Select name from table1 Group by name having (Count(*)>1))

ORDER BY Name

Visual Basic.net: Retrieve data from SQL Server database and navigation Buttons[ with source code ]

 

Imports System.Data.SqlClient

Public Class Form2

    Dim table As New DataTable

    Dim index As Integer

    Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        loadData(index)

    End Sub

    Public Sub loadData(ByVal position As Integer)

        Dim con1 As New SqlConnection("Data Source=prog-pc;Initial Catalog=d2;Integrated Security=True")

        Dim com1 As New SqlCommand("select id,firstname,lastname,telephone,sum from table1", con1)

       

        Dim adapter As New SqlDataAdapter(com1)

        adapter.Fill(table)

        TextBox1.Text = table.Rows(position)(0).ToString

        TextBox2.Text = table.Rows(position)(1).ToString

        TextBox3.Text = table.Rows(position)(2).ToString

        TextBox4.Text = table.Rows(position)(3).ToString

        TextBox5.Text = table.Rows(position)(4).ToString

    End Sub

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

        index = 0

        loadData(index)

    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

        index += 1

        loadData(index)

    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click

        index -= 1

        loadData(index)

    End Sub

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

        index = table.Rows.Count - 1

        loadData(index)

    End Sub

End Class