ASP.NET Core 6 Web API CRUD With Entity Framework

public class Contact {
    public Guid id {
        get;
        set;
    }
    public string name {
        get;
        set;
    }
    public string email {
        get;
        set;
    }
    public long phone {
        get;
        set;
    }
    public string address {
        get;
        set;
    }
}

public class ContactsAPIDbContext: DbContext {
    public ContactsAPIDbContext(DbContextOptions options): base(options) {}
    public DbSet < Contact > Contacts {
        get;
        set;
    }
}

Step 4

The program. cs file and inject this contacts API Db context into the services of the solution on to that injected service into a controller that we can connect to a database file and write below this line were injecting the service for swagger use the Builder.services and write at Db context because we want to add the Db context gives the type which is the contactsAPIDBcontext click control and import from contacts API data the one we created and after that, give some options to it which shows it to UseInMemoryDatabase so use InMemory database after that we have to give the database name ContactsDb

builder.Services.AddDbContext<ContactsAPIDbContext>(option =>
option.options.UseInMemoryDatabase("ContactsDb"));

Step 5

We add a new controller in the Controller folder and select MVC Controller_empty name as Contacts now we annotate our controller with the key Api controller telling this is an API controller which shows this is not an MVC controller after that we Route our controller

 [ApiController]
    [Route("api/[Controller]")]

Step 6

We use this private readonly field DbContext to connect to my in-memory database and will use this dot DbContext field to connect the contacts table

private ContactsAPIDbContext dbContext;
public ContactsController(ContactsAPIDbContext dbContext) {
    this.dbContext = dbContext;
}

Step 7

Because we've given the Db set property inside the contact, it understands that contacts are a table in a database, so connect to the contact table and return a list. Use this Db context to put a dot to connect to the contacts table. If it states that we are unable to convert type generic lists to IActionResults automatically, so we put in ok inside an ok response and its shows all the data stored in the contact table

[HttpGet]
public async Task < IActionResult > GetContacts() {
    return Ok(await dbContext.Contacts.ToListAsync());
}

Output

Step 8

In this step, we will add a contact using the AddContact method using the below C# code for HttpPost.

[HttpPost]
public async Task < IActionResult > AddContact(AddContactRequest addContactRequest) {
    var contact = new Contact() {
        id = Guid.NewGuid(),
            name = addContactRequest.Name,
            address = addContactRequest.Address,
            email = addContactRequest.Email,
            phone = addContactRequest.Phone,
    };
    await dbContext.Contacts.AddAsync(contact);
    await dbContext.SaveChangesAsync();
    return Ok(contact);
}

Output

Step 9

In the GetContact method, we only retrieve single data with the key parameter Guid id.

[HttpGet]
[Route("{id:guid}")]
public async Task < IActionResult > GetContact([FromRoute] Guid id) {
    var contact = await dbContext.Contacts.FindAsync(id);
    if (contact == null) {
        return NotFound();
    }
    return Ok(contact);
}

Output

Step 10

Now we will update the contact table with key parameter guide id and UpdateContactRequest model class firstly we store the value of Guid id in the contact variable check if it is null then shows not found result if the contact is not null then update the data of the contact and show 200 response.

[HttpPut]
[Route("{id:guid}")]
public async Task < IActionResult > UpdateContact([FromRoute] Guid id, UpdateContactRequest updateContactRequest) {
    var contact = await dbContext.Contacts.FindAsync(id);
    if (contact != null) {
        contact.name = updateContactRequest.name;
        contact.phone = updateContactRequest.phone;
        contact.address = updateContactRequest.address;
        contact.email = updateContactRequest.email;
        await dbContext.SaveChangesAsync();
        return Ok(contact);
    }
    return NotFound();
}

Output

Step 11

In this step, we will delete a contact with key parameter Guid id. Define a var type variable contact and store the parameter value check conditions if contact is null then shows not found, if contact is not null then remove a contact from the contact table and save the changes then return 200 response

[HttpDelete]
[Route("{id:guid}")]
public async Task < IActionResult > DeleteContact(Guid id) {
    var contact = await dbContext.Contacts.FindAsync(id);
    if (contact != null) {
        dbContext.Remove(contact);
        dbContext.SaveChanges();
        return Ok(contact);
    }
    return NotFound();
}

output

Step 12

Now implementing connection with SQL server, by adding connection string in appsettings.json

, "ConnectionStrings": {
    "ContactAPIConnectionString": "Server=LAPTOP-L9APCEGG\\MSSSQLSERVER; Database=ContactAPIDb; User id=sa; password=Password$2; Trusted_Connection=True; MultipleActiveResultSets=true"
}

Conclusion

In this article, we covered the topic of how we can create ASP.NET Core 6 Web API CRUD using Entity Framework.

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