In Day5, we successed to connect Microsoft Sql server and created a CustomerDB.
Naturally, we will try to get the data from database and use it for API.
Open SQL Server Management Studio (SSMS).
Expand Database Diagrams>expand Table>right click on dbo.Customer >Edit Top 200 Rows
Create 2 record
Go back to Visual Studio.
Open CustomerController.cs
CustomerController.cs
using CustomerAPI.Data;
using CustomerAPI.Entities;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
namespace CustomerAPI.Controllers
{
[Route("api/[controller]")]
[ApiController]
public class CustomerController : ControllerBase
{
private readonly DataContext _context;
public CustomerController(DataContext context) {
_context = context;
}
[HttpGet]
public async Task<IActionResult> GetCustomers()
{
var customers = await _context.Customers.ToListAsync();
return Ok(customers);
}
}
}
We can test it on Postman
Success!
What if we just want to get 1 specific record only?
We can specify a id in the Route.
CustomerController.cs
using CustomerAPI.Data;
using CustomerAPI.Entities;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
namespace CustomerAPI.Controllers
{
[Route("api/[controller]")]
[ApiController]
public class CustomerController : ControllerBase
{
private readonly DataContext _context;
public CustomerController(DataContext context) {
_context = context;
}
[HttpGet]
public async Task<IActionResult> GetCustomers()
{
var customers = await _context.Customers.ToListAsync();
return Ok(customers);
}
[HttpGet("{id}")]
public async Task<IActionResult> GetCustomerById(int id)
{
var customers = await _context.Customers.FindAsync(id);
if(customers == null)
{
return BadRequest("Customer not found");
}
return Ok(customers);
}
}
}
We use [HttpGet("{id}")] to retrieve the id from the URL and to get the record from CustomerDB by the id.
And we also have to checking if the record if valid or not.
If the record is not found, return a BadRequest(400) or NotFound(404).
Let test it on Postman.
Success!
Also the not found respond.
