3 tier Architecture

Question

How to code for a search button in tier architecture, I'm using SQL Server and Visual Studio 2019

Sachin Singh · Answer

BusinessEntity public class Employee // employee is any class { public int Id{ get ; set ;} public string Name { get ; set ;} } Business Logic public class EmployeeBL { public List Search( string searchTerm) { EmployeeDAL db= new EmployeeDAL(); return db.GetAllEmployees().Where(x=>x.Id.ToString()==searchTerm ||x.Name==searchTerm).ToList(); } } DataAccess public class EmployeeDAL { public List GetAllEmployees() { List emps= new List (); using (SqlConnection con= new SqlConnection( "yr connection string" )) { SqlCommand cmd= new SqlCommand( "select * from tblEmployee" ,con); con.Open(); SqlDataReader rdr=cmd.ExecuteReader(); while (rdr.Read()) { Employee emp= new Employee(); emp.Id=Convert.ToInt32(rdr[ "Id" ]); emp.Name=rdr[ "Name" ].ToString(); emps.Add(emp); } } return emps; } } UI layer private void btnSearch_Click(eventArgs.......) { EmployeeBL empbl= new EmployeeBL(); var emps=empbl. Search(txtSearch.Text); // do whatever you want to do with searched data }

satheesh d · Answer

Lets take ths API controller which returns the list of books stored in the data base. And I have used the entity framework for connecting the database to my data access layer. In that I have created a sample API get method which can all the list of books (sample library management) stored in connected database. private APILibraryEntities db = new APILibraryEntities(); // GET: api/Tbl_Books public IQueryable GetTbl_Books() { return db.Tbl_Books. Where (x => x.IsActive==1); } Now we can consume this API from the another controller and can apply filter (filter the books based on the Author Name) and then call this from the User Interface. public ActionResult Index( string search) { IEnumerable BooksList; HttpResponseMessage response = GlobalVariables.webApiClient.GetAsync( "Tbl_Books" ).Result; BooksList = response.Content.ReadAsAsync >().Result; if (search == null ) { return View(BooksList.Where(x => x.IsActive == 1).ToList()); } else { return View(BooksList.Where(x => x.AuthorName.StartsWith(search) || search == null ).ToList()); } } @Html.PagedListPager(Model, i => Url.Action( "Index" , "Library" , new { search = Request.QueryString[ "search" ] })) This is sample way to inserting search button in the application. We can also filter the records even in the API controller by using the Linq query concepts.

Jignesh Kumar · Answer

Hi, Please refer this link which will help you, https://www.c-sharpcorner.com/article/building-a-3-tier-application-using-Asp-Net/