In this article, we will implement a sample application .Net5 Razor Pages CRUD operations using entity framework core.
Endpoint Middleware - Middleware to set up the routing for our razor page application. This configuration is done in 'Startup.cs'
_ViewImports.cshtml - File used to configure application namespaces
_ViewStart.cshtml - File helps to load the master layout template.
Shared/_Layout.cshtml - Default master template.
Entity Framework Core:
step2:
step3:
Razor Pages:
Razor Page is a simplified web application model. On comparing with 'MVC' template, razor pages won't have 'Controller', which means razor pages is a combination of 'Views' and 'Models'. Routing itself configured within the page or view. A razor page mostly contains 2 files like 'filename.cshtml'(view) and 'filename.cshtml.cs'(model).
Create A .Net5 Razor Page Application:
Begin our journey by creating a .Net5 razor page template application.
Visual Studio users it is very easy to create razor applications by selecting the template option like 'ASP.NET Core Web APP'.
Here I'm using a visual studio code editor and .Net CLI commands to generate the application.
Here I'm using a visual studio code editor and .Net CLI commands to generate the application.
CLI Command To Create Razor Page Application:
dotnet new webapp -n your_project_name
After creating the project few basic things we must aware of like:Endpoint Middleware - Middleware to set up the routing for our razor page application. This configuration is done in 'Startup.cs'
_ViewStart.cshtml - File helps to load the master layout template.
Shared/_Layout.cshtml - Default master template.
wwwroot - Folder to maintain static files like 'css', 'js', 'images', etc.
appsettings.{environment variable name}.json - Configuration file.
Entity Framework Core:
Entity Framework Core is an Object/Relational Mapping(ORM) framework. EF Core makes database communication more fluent and easy.
EF Core supports:
Code First Approach means first we will create c# POCO classes and then create the database tables. Code First Approach has one more sub-category like 'Code First With Existing Database'. So the 'Code First With Existing Database' can work with the already created tables in the database which is an ideal choice for real-time development. Our demo will be implemented using 'Code First With Existing Database'.- Database First Approach.
- Code First Approach.
Install EF Core Nuget:
Now install ef core and SQL ef core extension Nuget package into our application.
Package Manager(Visual Studio):
Install-Package Microsoft.EntityFrameworkCore -Version 5.0.6
Install-Package Microsoft.EntityFrameworkCore.SqlServer -Version 5.0.6
CLI Commands(Visual Studio Code):
dotnet add package Microsoft.EntityFrameworkCore --version 5.0.6
dotnet add package Microsoft.EntityFrameworkCore.SqlServer --version 5.0.6
Sample SQL Script:
To follow the demo, run the SQL script to generate the table.
CREATE TABLE [dbo].[Gadgets]( [Id] [int] IDENTITY(1,1) NOT NULL, [ProductName] [varchar](max) NULL, [Brand] [varchar](max) NULL, [Cost] [decimal](18, 0) NOT NULL, [ImageName] [varchar](1024) NULL, [Type] [varchar](128) NULL, [CreatedDate] [datetime] NULL, [ModifiedDate] [datetime] NULL, PRIMARY KEY CLUSTERED ( [Id] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
Setup EF Core DbContext:
First, let's create POCO class that represents our table. So let's create a new folder 'Data', inside of it create one more folder like 'Entities'. Inside of the 'Entities' folder creates our POCO class.
Data/Entities/Gadgets.cs:
namespace Dotnet5.RazorPage.EF.CRUD.Data.Entities { public class Gadgets { public int Id { get; set; } public string ProductName { get; set; } public string Brand { get; set; } public decimal Cost { get; set; } public string Type { get; set; } } }In EF Core DbContext is like a database that manages all POCO classes(classes represent tables). Inside the 'Data' folder create a context class.
Data/MyWorldDbContext.cs:
using Dotnet5.RazorPage.EF.CRUD.Data.Entities; using Microsoft.EntityFrameworkCore; namespace Dotnet5.RazorPage.EF.CRUD.Data { public class MyWorldDbContext : DbContext { public MyWorldDbContext(DbContextOptions<MyWorldDbContext> options) : base(options) { } public DbSet<Gadgets> Gadgets { get; set; } } }Add database connection string into 'appsetting.Development.json'
appsetting.Development.json:
"ConnectionStrings":{ "MyWorldDbConnection":"your_connection" }Register 'MyWorlDbContext' into the dependency services.
Startup.cs:
services.AddDbContext<MyWorldDbContext>(options => { options.UseSqlServer(Configuration.GetConnectionString("MyWorldDbConnection")); });
Read Operation:
Create a folder 'Gadgets' inside of the 'Pages' folder and then add razor page like 'Gadget.cshtml'(view) and 'Gadget.cshtml.cs'(model).
Pages/Gadgets/Gadget.cshtml.cs:
using System.Collections.Generic; using System.Linq; using System.Threading.Tasks; using Dotnet5.RazorPage.EF.CRUD.Data; using Microsoft.AspNetCore.Mvc.RazorPages; using Microsoft.EntityFrameworkCore; namespace Dotnet5.RazorPage.EF.CRUD.Pages.Gadgets { public class GadgetModel : PageModel { public List<Data.Entities.Gadgets> AllGadgets = new List<Data.Entities.Gadgets>(); private readonly MyWorldDbContext _myWorldDbContext; public GadgetModel(MyWorldDbContext myWorldDbContext) { _myWorldDbContext = myWorldDbContext; } public async Task OnGetAsync() { AllGadgets = await _myWorldDbContext.Gadgets.OrderByDescending(_ => _.Id).ToListAsync(); } } }
- (Line: 10) To make our class file as a razor page model it needs to inherit 'Microsoft.AspNetCore.Mvc.RazorPages.PageModel'.
- (Line: 12) Declare variable 'AllGadgets' which will be used to store the data from the database and this variable will be used in the 'Gadget.cshtml'(view) file for data binding.
- (Line: 14-18) Injected the database context.
- (Line: 20-23) The default method executed for the razor page HTTP Get request is 'OnGet' or 'OnGetAsync'. It is always ideal to have one get method in razor pages. If you want to customize the name of the HTTP Get request method then it should be like 'OnGet{YourCustomName}' or 'OnGet{YourCustomName}Async', but if we customize the method name then we have to specify the custom name as a value to the query parameter 'handler'. So don't give the custom name unless it is required. Inside of our 'OnGetAsync' method we need to write our logic to fetch the data from the database.
@page "/all-gadgets" @model GadgetModel <div> <table class="table table-dark table-striped"> <thead> <tr> <th scope="col">Id</th> <th scope="col">Product Name</th> <th scope="col">Brand</th> <th scope="col">Cost</th> <th scope="col">Type</th> </tr> </thead> <tbody> @foreach (var item in Model.AllGadgets) { <tr> <th scope="row">@item.Id</th> <td>@item.ProductName</td> <td>@item.Brand</td> <td>@item.Cost</td> <td>@item.Type</td> </tr> } </tbody> </table> </div>
- (Line: 1) The '@page' directive used for configuring the route.
- (Line: 2) Define the 'Model' object.
- (Line: 15-24) Looping the data to bind to the table.
Create Operation:
In 'Pages/Gadgets' folder create new razor pages for creation like 'CreateGadget.cshtml'(view) and 'CreateGadget.cshtml.cs'(model).
Pages/Gadgets/CreateGadget.cshtml.cs:
using System.Threading.Tasks; using Dotnet5.RazorPage.EF.CRUD.Data; using Microsoft.AspNetCore.Mvc; using Microsoft.AspNetCore.Mvc.RazorPages; namespace Dotnet5.RazorPage.EF.CRUD.Pages.Gadgets { public class CreateGadgetModel : PageModel { [BindProperty] public Data.Entities.Gadgets NewGadget { get; set; } private readonly MyWorldDbContext _myWorldDbContext; public CreateGadgetModel(MyWorldDbContext myWorldDbContext) { _myWorldDbContext = myWorldDbContext; } public IActionResult OnGetAsync() { return Page(); } public async Task<IActionResult> OnPostAsync() { _myWorldDbContext.Gadgets.Add(NewGadget); await _myWorldDbContext.SaveChangesAsync(); return Redirect("all-gadgets"); } } }
- (Line: 10-11) The 'NewGadget' property decorated with the 'BindProperty' attribute, so this attribute will read the form posted data and store into the property.
- (Line: 18-21) The 'OnGetAsync' method invoked for HTTP Get request, it just renders the page.
- (Line: 23-28) The 'OnPostAsync' method invokes the HTTP post request, which means this will technically get invoked on a form post. So we know the 'BindProperty' attribute helps the property to store the form data, so we can save that to the database.
@page "/creategadget" @model CreateGadgetModel <div> <form method="POST"> <div class="mb-3"> <label for="txtProductName" class="form-label">Product Name</label> <input asp-for="NewGadget.ProductName" type="text" class="form-control" id="txtProductName" > </div> <div class="mb-3"> <label for="txtBrand" class="form-label">Brand</label> <input asp-for="NewGadget.Brand" type="text" class="form-control" id="txtBrand"> </div> <div class="mb-3"> <label for="txtCost" class="form-label">Cost</label> <input asp-for="NewGadget.Cost" type="text" class="form-control" id="txtCost"> </div> <div class="mb-3"> <label for="txtType" class="form-label">Type</label> <input asp-for="NewGadget.Type" type="text" class="form-control" id="txtType"> </div> <button type="submit" class="btn btn-primary">Submit</button> </form> </div>
- Here on every input filed we used binded 'asp-for' razor HTML attribute, this makes form to load the data on submission. The 'asp-for' value must be our 'NewGadget' type properties.
Pages/Gadgets/Gadget.cshtml:
@page "/all-gadgets" @model GadgetModel <!-- Code hidden for display purpose --> <div> <a asp-page="./creategadget" class="btn btn-primary">Create New Gadget</a> <table class="table table-dark table-striped"> </table> </div>
- (Line: 5) Add a button that going to navigate to the 'CreateGadgets.cshtml' page. Here used 'asp-page' razor attribute for defining our route.
step2:
step3:
Update Operation:
In the 'Pages/Gagets' folder create pages like 'EditGadget.cshtml' and 'EditGadget.cshtml.cs' for update operation.Pages/Gadget/EditGadget.cshtml.cs:
using System.Linq; using System.Threading.Tasks; using Dotnet5.RazorPage.EF.CRUD.Data; using Microsoft.AspNetCore.Mvc; using Microsoft.AspNetCore.Mvc.RazorPages; using Microsoft.EntityFrameworkCore; namespace Dotnet5.RazorPage.EF.CRUD.Pages.Gadgets { public class EditGadgetModel : PageModel { [BindProperty] public Data.Entities.Gadgets GadgetToUpdate { get; set; } private readonly MyWorldDbContext _myWorldDbContext; public EditGadgetModel(MyWorldDbContext myWorldDbContext) { _myWorldDbContext = myWorldDbContext; } public async Task<IActionResult> OnGetAsync(int id) { GadgetToUpdate = await _myWorldDbContext.Gadgets.Where(_ => _.Id == id).FirstOrDefaultAsync(); if (GadgetToUpdate == null) { return Redirect("~/all-gadgets"); } return Page(); } public async Task<IActionResult> OnPostAsync() { _myWorldDbContext.Attach(GadgetToUpdate).State = EntityState.Modified; await _myWorldDbContext.SaveChangesAsync(); return Redirect("~/all-gadgets"); } } }
- (Line: 21-30) The 'OnGetAsync' method reads the 'id' value from the route. So from this, we can determine that HTTP request methods can read the route values as their input parameters. So based on 'id' value we will fetch records from the database.
- (Line: 32-37) The 'OnPostAsync' method updating the data to the database.
@page "/edit/{id:int}" @model EditGadgetModel <div> <form method="POST"> <input asp-for="GadgetToUpdate.Id" type="hidden" class="form-control" id="txtProductName" > <div class="mb-3"> <label for="txtProductName" class="form-label">Product Name</label> <input asp-for="GadgetToUpdate.ProductName" type="text" class="form-control" id="txtProductName" > </div> <div class="mb-3"> <label for="txtBrand" class="form-label">Brand</label> <input asp-for="GadgetToUpdate.Brand" type="text" class="form-control" id="txtBrand"> </div> <div class="mb-3"> <label for="txtCost" class="form-label">Cost</label> <input asp-for="GadgetToUpdate.Cost" type="text" class="form-control" id="txtCost"> </div> <div class="mb-3"> <label for="txtType" class="form-label">Type</label> <input asp-for="GadgetToUpdate.Type" type="text" class="form-control" id="txtType"> </div> <button type="submit" class="btn btn-primary">Submit</button> </form> </div>
- Here 'EditGadget.cshtml' Html code almost the same as Html code in 'CreateGadget.cshtml', the only difference is we will store the record primary value as a hidden field.
Pages/Gadgets/Gadget.cshtml:
@page "/all-gadgets" @model GadgetModel <!-- code hidden for display purpose --> <div> <a asp-page="./creategadget" class="btn btn-primary">Create New Gadget</a> <table class="table table-dark table-striped"> <thead> <tr> <th scope="col">Actions</th> </tr> </thead> <tbody> @foreach (var item in Model.AllGadgets) { <tr> <td> <a href='@($"/edit/{item.Id}")' class="btn btn-primary">Edit</a> | </td> </tr> } </tbody> </table> </div>
- (Line: 9) Added new column like 'Actions'.
- (Line: 7) Edit button for respective record of the table.
step2:
step:3
step:3
Delete Operation:
Now for the delete operation, we will implement an HTTP post method inside of the 'Gadget.cshmtl.cs' file. So instead of using 'OnPostAsync' as the method name, we will customize the method name as 'OnPostDeleteAsync'.
Pages/Gadgets/Gadgets.cshtml.cs:
namespace Dotnet5.RazorPage.EF.CRUD.Pages.Gadgets { public class GadgetModel : PageModel { // code hidden for displya purpose public async Task<IActionResult> OnPostDeleteAsync(int id) { var currentGadget = await _myWorldDbContext.Gadgets.FindAsync(id); if (currentGadget != null) { _myWorldDbContext.Gadgets.Remove(currentGadget); await _myWorldDbContext.SaveChangesAsync(); } return Redirect("~/all-gadgets"); } } }
- This method get executed for a HTTP post-call and URL should be like 'http:yourdomain/all-gadgets?id={idvalue}&handler=delete'. Inside of this method implementing logic to delete the recorded from the database.
@page "/all-gadgets" @model GadgetModel <!-- code hidden for display purpose --> <div> <a asp-page="./creategadget" class="btn btn-primary">Create New Gadget</a> <table class="table table-dark table-striped"> <tbody> @foreach (var item in Model.AllGadgets) { <tr> <td> <a href='@($"/edit/{item.Id}")' class="btn btn-primary">Edit</a> | <button type="button" onclick="deleteGadget(@item.Id)" class="btn btn-primary">delete </button> </td> </tr> } </tbody> </table> </div> <div class="modal fade" id="deleteGadgetModal" tabindex="-1" aria-labelledby="exampleModalLabel" aria-hidden="true"> <div class="modal-dialog"> <div class="modal-content"> <div class="modal-body"> <h4>Are you sure, you want to delete?</h4> </div> <div class="modal-footer"> <button type="button" class="btn btn-secondary" onclick="closeModal()" data-bs-dismiss="modal">Close</button> <form method="POST" id="confirmDelete"> <button type="submit" class="btn btn-primary">delete</button> </form> </div> </div> </div> </div>
- (Line: 14-15) Added the 'Delete' button. Delete button registered with a click event method like 'deleteGadget()'.
- (Line: 24-39) Add the Html for bootstrap 'Modal'.
- (Line: 32) Added operation cancel button, registered with a click event method like 'closeModal()'.
- (Line: 33-35) Confirm delete button enclosed in a form, so that on clicking button post-operation will be activated.
wwwroot/js/site.js:
function deleteGadget(id) { url = "/all-gadgets?id=" + id + "&handler=delete"; var deleteFormEl = document.getElementById("confirmDelete"); deleteFormEl.setAttribute("action", url); $("#deleteGadgetModal").modal("show"); } function closeModal() { $("#deleteGadgetModal").modal("hide"); }
- The 'deleteGadget(id)' method prepares the delete post URL and binds the URL to a form on the Bootstrap Modal.
- The 'closeModal' method to close the BootstrapModal.
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Wrapping Up:
Hopefully, I think this article delivered some useful information on .Net5 Razor Pages CRUD operation with the entity framework. I love to have your feedback, suggestions, and better techniques in the comment section below.
Love your tutorial! Hope you can post how to put more entities and related entities.
ReplyDeleteThanks for sharing!