Vb.net Code To Retrieve Data From Sql Server -

Imports System.Data.SqlClient Public Function GetEmployeesAsDataTable() As DataTable Dim dataTable As New DataTable() Dim connectionString As String = "Server=localhost;Database=YourDatabase;Integrated Security=True;"

Using connection As New SqlConnection(connectionString) Dim query As String = "SELECT EmployeeID, FirstName, LastName, Department, Salary FROM Employees" Dim command As New SqlCommand(query, connection) Try connection.Open() Dim reader As SqlDataReader = command.ExecuteReader() While reader.Read() Dim emp As New Employee() emp.EmployeeID = Convert.ToInt32(reader("EmployeeID")) emp.FirstName = reader("FirstName").ToString() emp.LastName = reader("LastName").ToString() emp.Department = reader("Department").ToString() emp.Salary = Convert.ToDecimal(reader("Salary")) employees.Add(emp) End While reader.Close() Catch ex As SqlException MessageBox.Show("SQL Error: " & ex.Message) End Try End Using

DataGridView1.DataSource = employees Label1.Text = $"Loaded employees.Count records" Button1.Enabled = True End Sub Here's a complete working example with a helper class: vb.net code to retrieve data from sql server

Public Function GetEmployeesByDepartment(deptName As String) As DataTable Dim dataTable As New DataTable() Dim connectionString As String = "Server=localhost;Database=YourDatabase;Integrated Security=True;" Using connection As New SqlConnection(connectionString) Dim query As String = "SELECT EmployeeID, FirstName, LastName, Salary FROM Employees WHERE Department = @Department" Dim command As New SqlCommand(query, connection) ' Add parameter to prevent SQL injection command.Parameters.AddWithValue("@Department", deptName) Dim adapter As New SqlDataAdapter(command) Try adapter.Fill(dataTable) Catch ex As SqlException MessageBox.Show("Error: " & ex.Message) End Try End Using

Return employees End Function This approach loads all data into memory and works well for data binding. Imports System

Private Async Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click ' Show loading indicator Button1.Enabled = False Label1.Text = "Loading data..." Dim employees As List(Of Employee) = Await GetEmployeesAsync()

Imports System.Data.SqlClient Public Async Function GetEmployeesAsync() As Task(Of List(Of Employee)) Dim employees As New List(Of Employee)() Dim connectionString As String = "Server=localhost;Database=YourDatabase;Integrated Security=True;" vb.net code to retrieve data from sql server

' Employee class definition Public Class Employee Public Property EmployeeID As Integer Public Property FirstName As String Public Property LastName As String Public Property Department As String Public Property Salary As Decimal Public ReadOnly Property FullName As String Get Return $"FirstName LastName" End Get End Property End Class

Return count End Function Always use parameters when filtering data.

Public Function GetEmployeeCount() As Integer Dim count As Integer = 0 Dim connectionString As String = "Server=localhost;Database=YourDatabase;Integrated Security=True;" Using connection As New SqlConnection(connectionString) Dim query As String = "SELECT COUNT(*) FROM Employees" Dim command As New SqlCommand(query, connection) Try connection.Open() count = Convert.ToInt32(command.ExecuteScalar()) Catch ex As SqlException MessageBox.Show("Error: " & ex.Message) End Try End Using

Return dataTable End Function For Windows Forms or WPF applications, use async methods to keep the UI responsive.