In the previous posting we saw how to create an API to get all the cars in our database. In this posting we’ll look at the remaining CRUD (Create Review Update Delete) operations.
As you may remember, we created a controller named CarController. ASP.NET will strip off the word Controller, leaving us with Car, which we will use to access the endpoints of our API.
An endpoint is just a URL that takes us to the operation we want.
We looked at GetAll, let’s take a look at Get. In this case, we have an id for the car we want, but we want all the details of that car. Simple!
First we need a method in our controller:
[HttpGet("{id}")]
public async Task<ActionResult<Car>> Get(int id)
{
var car = await _carRepository.Get(id);
if (car == null)
{
return NotFound();
}
return car;
}
Notice that next to the HttpGet attribute we indicate that the endpoint will take the id of the car we want
[HttpGet("{id}")]
This means we need to modify the URL to access the endpoint by adding the actual id of the desired record.
The first thing we do is call the repository, passing in the id.
public async Task<Car?> Get(int id)
{
var query = "select * from car where id=@id";
using var db = databaseConnectionFactory.GetConnection();
return await db.QuerySingleOrDefaultAsync<Car>(query, new {id});
}
In the Get method of the repo we create our query, get our connection and execute the query returning the value we retrieved (if any). This is very close to what we did previously.
Back in the controller, we check to ensure that we received a Car. If not, we return NotFound which is a shorthand way of returning a 404 message. Otherwise we return the Car as a Json object. You can see this in Postman:
We’ll issue a Get command passing in the URL, ending with the id of the car we want (in this case 4)
Notice that we get back a 200, indicating success. In the body of the returned Json we get back all the details of the Car. (If you decide to use DTOs you can get whatever subset of the information makes sense):
Post
Adding a Car to the database is quite similar. We need a method in the controller and one in the repo. Here is the controller method:
[HttpPost]
public async Task<ActionResult<Car>> Post([FromBody] Car car)
{
try
{
car = await _carService.Insert(car);
}
catch (Exception e)
{
return BadRequest(e);
}
return CreatedAtAction(nameof(Get), new { id = car.Id }, car);
}
Look at the attribute in the parameter ([FromBody]. This indicates to the API that the data needed to insert this Car will be in the body of the call. The alternative is FromQuery. You can, in fact, use both in one call.
Note: CreatedAction causes a return code of 201, which is what we want. Here’s the body we’ll insert:
When we click Send this data is sent to the API which returns 201 (created) and in the body of the returned data we see the new id assigned to this car
Service Class
Notice that this time, instead of calling the Repo directly, the method in the controller calls into a service class. A service class is a great way to get the logic out of the controller, where it does not belong, without putting it into the repo, where it also does not belong.
Here’s the top of the CarService
public class CarService : ICarService
{
private readonly ICarRepository _carRepository;
public CarService(ICarRepository carRepository)
{
_carRepository = carRepository;
}
public async Task<Car> Insert(Car car)
{
var newId = await _carRepository.UpsertAsync(car);
if (newId > 0)
{
car.Id = newId;
}
else
{
throw new Exception("Failed to insert car");
}
return car;
}
All the logic associated with this insert (e.g., making sure we get back a legitimate id from the repository, etc.) is encapsulated in the service.
This leaves the repository free to just talk to the database,
public async Task<int> UpsertAsync(Car car)
{
using var db = databaseConnectionFactory.GetConnection();
var sql = @"
DECLARE @InsertedRows AS TABLE (Id int);
MERGE INTO Car AS target
USING (SELECT @Id AS Id, @Name AS Name, @Model_Year AS Model_Year,
@Is_Deleted AS Is_Deleted, @Origin AS origin ) AS source
ON target.Id = source.Id
WHEN MATCHED THEN
UPDATE SET
Name = source.Name,
Model_Year = source.Model_Year,
Is_Deleted = source.Is_Deleted,
Origin = source.Origin
WHEN NOT MATCHED THEN
INSERT (Name, Model_Year, Is_Deleted, Origin)
VALUES (source.Name, source.Model_Year,
source.Is_Deleted, source.Origin)
OUTPUT inserted.Id INTO @InsertedRows
;
SELECT Id FROM @InsertedRows;
";
var newId = await db.QuerySingleOrDefaultAsync<int>(sql, car);
return newId == 0 ? car.Id : newId;
}
Rather than having an insert and an update method, we combine that logic into this upsert method. This is a common idiom for database manipulation.
Note: to make this work, be sure to fill in all the fields for a car (or at least as many as you want to have in the Database.
Delete
As noted earlier, we will implement a soft delete; that is, rather than actually removing the data from the database, we’ll just set the is_deleted column to true. This allows us to reverse the action, and make the row not-deleted by simply changing that value to false.
[HttpDelete(“{id}”)]
public async Task<IActionResult> Delete(int id)
{
try
{
await _carService.Delete(id);
}
catch (Exception e)
{
return BadRequest(e);
}
return NoContent();
}
As you would expect, the endpoint takes an id (the id of the car we want to delete). The controller then hands that off to the service, which calls the repository which, in turn, marks that id as deleted:
public async Task<int> DeleteAsync(int id)
{
using var db = databaseConnectionFactory.GetConnection();
var query = "UPDATE car SET Is_Deleted = 1 WHERE Id = @Id";
return await db.ExecuteAsync(query, new { Id = id });
}
If you are comfortable with SQL none of this will be very surprising. The key walkaway is:
Summary
In this post we saw that endpoints are just URLs with (potentially) data in the body of the request. The controller handles the URL and in our case passes the id or other data to the service. The service handles the (business) logic and then delegates talking to the database to the repository.
Book
This posting is excerpted from my forthcoming book Building APIs with .NET and C# to be released next year by Packt.
Excellent article. Keep writing such kind of info on your site. Im really impressed by your site.
https://medmexico.online/# mexico pet pharmacy
Wow that was strange. I just wrote an incredibly long comment but after I clicked submit my comment didn’t show up. Grrrr… well I’m not writing all that over again. Anyhow, just wanted to say superb blog!
Can I simply just say what a comfort to find somebody who truly knows what they are discussing on the internet. You actually realize how to bring a problem to light and make it important. A lot more people have to look at this and understand this side of your story. It’s surprising you aren’t more popular given that you definitely have the gift.
Hey there, You’ve done a fantastic job. I will definitely digg it and in my view suggest to my friends. I am confident they will be benefited from this web site.
farmacias online seguras: farmacia online espaГ±a envГo internacional – farmacia online madrid
Currently it appears like WordPress is the best blogging platform out there right now. (from what I’ve read) Is that what you’re using on your blog?
Hey I know this is off topic but I was wondering if you knew of any widgets I could add to my blog that automatically tweet my newest twitter updates. I’ve been looking for a plug-in like this for quite some time and was hoping maybe you would have some experience with something like this. Please let me know if you run into anything. I truly enjoy reading your blog and I look forward to your new updates.
Currently it seems like Expression Engine is the best blogging platform out there right now. (from what I’ve read) Is that what you’re using on your blog?
Excellent pieces. Keep posting such kind of information on your site. Im really impressed by it.
https://farmaciaspain.online/# farmacias online seguras
Aw, this was a very good post. Finding the time and actual effort to make a really good article… but what can I say… I hesitate a whole lot and don’t manage to get anything done.
Aw, this was an extremely good post. Finding the time and actual effort to make a good article… but what can I say… I hesitate a whole lot and don’t seem to get nearly anything done.
杖与剑的魔剑谭不会魔法照样一路逆袭，战斗过程燃到停不下来高清免费点击观看
Currently it sounds like Movable Type is the top blogging platform out there right now. (from what I’ve read) Is that what you’re using on your blog?
buy cymbalta online: cymbalta – cymbalta for pain
https://cymbalta.top/# cymbalta duloxetine
Aw, this was an exceptionally nice post. Spending some time and actual effort to make a very good article… but what can I say… I hesitate a whole lot and never seem to get anything done.
Hi there, You have performed a great job. I’ll certainly digg it and in my opinion recommend to my friends. I am sure they will be benefited from this website.
Greate post. Keep posting such kind of information on your blog. Im really impressed by your blog.
May I simply say what a comfort to uncover somebody that really knows what they’re talking about on the internet. You certainly know how to bring a problem to light and make it important. More and more people really need to check this out and understand this side of the story. I can’t believe you are not more popular because you surely possess the gift.
Aw, this was a really good post. Taking the time and actual effort to produce a good article… but what can I say… I hesitate a whole lot and never seem to get nearly anything done.
Hello there, You’ve done an excellent job. I will certainly digg it and for my part suggest to my friends. I’m confident they will be benefited from this web site.
Hey I know this is off topic but I was wondering if you knew of any widgets I could add to my blog that automatically tweet my newest twitter updates. I’ve been looking for a plug-in like this for quite some time and was hoping maybe you would have some experience with something like this. Please let me know if you run into anything. I truly enjoy reading your blog and I look forward to your new updates.
Hey I know this is off topic but I was wondering if you knew of any widgets I could add to my blog that automatically tweet my newest twitter updates. I’ve been looking for a plug-in like this for quite some time and was hoping maybe you would have some experience with something like this. Please let me know if you run into anything. I truly enjoy reading your blog and I look forward to your new updates.
At this time it seems like Expression Engine is the top blogging platform available right now. (from what I’ve read) Is that what you’re using on your blog?
nootropic Modafinil shipped to USA: smart drugs online US pharmacy – where to buy Modafinil legally in the US
Aw, this was an exceptionally nice post. Finding the time and actual effort to produce a very good article… but what can I say… I hesitate a lot and don’t seem to get anything done.
Wow that was unusual. I just wrote an incredibly long comment but after I clicked submit my comment didn’t show up. Grrrr… well I’m not writing all that over again. Anyway, just wanted to say fantastic blog!
May I simply say what a relief to find someone who actually knows what they’re talking about on the web. You actually realize how to bring a problem to light and make it important. A lot more people ought to look at this and understand this side of your story. It’s surprising you are not more popular given that you most certainly have the gift.
Can I simply say what a comfort to find someone that actually understands what they’re discussing on the web. You definitely know how to bring an issue to light and make it important. More people need to read this and understand this side of the story. I was surprised you are not more popular given that you definitely possess the gift.
Excellent article. Keep writing such kind of information on your site. Im really impressed by it.
Обращаем внимание, что таблица носит ознакомительный характер. Точную программу лечения и финальную цену определяет врач после осмотра и необходимых анализов. Врач нарколог бесплатно ответит на все ваши вопросы по услуге вывода из запоя на дому и оформит вызов врача.
Получить дополнительную информацию – vyvod-iz-zapoya-s-vyezdom
prescription-free Modafinil alternatives: WakeMeds RX – order Provigil without prescription
如果你喜欢爱情，这部作品绝对值得剧透。它以1080P的制作水准赢得了业界认可。 免费随时随地
Веб-сайт oopalkna.space — це елегантний і практичний збірка новинних сайтів України під назвою newsmap.
На сторінці зібрано перевірені українські джерела.
Сайт повністю адаптивний під будь-які пристрої, має лаконічний дизайн у сучасному стилі (Tailwind CSS), зручну навігацію та чіткі посилання на джерела.
Каталог періодично оновлюється, а користувачі можуть пропонувати нові сайти. Відмінний інструмент для оперативного доступу до якісних українських медіа та спеціалізованих ресурсів
Aw, this was a very good post. Taking the time and actual effort to generate a good article… but what can I say… I hesitate a whole lot and never manage to get nearly anything done.
Aw, this was an exceptionally good post. Taking a few minutes and actual effort to produce a top notch article… but what can I say… I hesitate a whole lot and never seem to get nearly anything done.
Currently it sounds like BlogEngine is the best blogging platform out there right now. (from what I’ve read) Is that what you are using on your blog?
Hey I know this is off topic but I was wondering if you knew of any widgets I could add to my blog that automatically tweet my newest twitter updates. I’ve been looking for a plug-in like this for quite some time and was hoping maybe you would have some experience with something like this. Please let me know if you run into anything. I truly enjoy reading your blog and I look forward to your new updates.
https://cymbalta.top/# cymbalta medication
Hey there, You’ve performed an incredible job. I’ll certainly digg it and personally suggest to my friends. I am sure they’ll be benefited from this web site.
Excellent article. Keep writing such kind of info on your page. Im really impressed by it.
Right now it seems like WordPress is the preferred blogging platform out there right now. (from what I’ve read) Is that what you’re using on your blog?
Hey I know this is off topic but I was wondering if you knew of any widgets I could add to my blog that automatically tweet my newest twitter updates. I’ve been looking for a plug-in like this for quite some time and was hoping maybe you would have some experience with something like this. Please let me know if you run into anything. I truly enjoy reading your blog and I look forward to your new updates.
Aw, this was an exceptionally nice post. Taking a few minutes and actual effort to generate a very good article… but what can I say… I hesitate a lot and don’t manage to get nearly anything done.
Wow that was unusual. I just wrote an really long comment but after I clicked submit my comment didn’t appear. Grrrr… well I’m not writing all that over again. Anyhow, just wanted to say fantastic blog!
Hey I know this is off topic but I was wondering if you knew of any widgets I could add to my blog that automatically tweet my newest twitter updates. I’ve been looking for a plug-in like this for quite some time and was hoping maybe you would have some experience with something like this. Please let me know if you run into anything. I truly enjoy reading your blog and I look forward to your new updates.
Hi there, You’ve done a fantastic job. I’ll definitely digg it and in my opinion suggest to my friends. I am confident they’ll be benefited from this web site.
Excellent pieces. Keep writing such kind of information on your blog. Im really impressed by your site.