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

CREATE TABLE Employees ( EmployeeID INT PRIMARY KEY IDENTITY(1,1), FirstName NVARCHAR(50), LastName NVARCHAR(50), Department NVARCHAR(50), Salary DECIMAL(10,2) ); SqlDataReader provides the fastest read performance for large result sets but is read-only and forward-only.

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;" vb.net code to retrieve data from sql server

Return dataTable End Function

Private Sub LoadDataToGrid() Dim dt As DataTable = GetEmployeesAsDataTable() DataGridView1.DataSource = dt End Sub Use ExecuteScalar when you expect a single value (e.g., COUNT, SUM, or a specific field). vb.net code to retrieve data from sql server

' Database Helper Class Public Class EmployeeDB Private Shared ReadOnly 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 vb.net code to retrieve data from sql server

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.