asp.net core 6.0 efcore +sqlserver增删改查的demo

asp.net core 6.0 efcore +sqlserver增删改查的demo

下面是一个使用ASP.NET Core 5.0和Entity Framework Core进行增删改查操作的示例。

首先，创建一个空的ASP.NET Core 6.0 Web应用程序项目。

然后，安装以下NuGet包：

Microsoft.EntityFrameworkCore.SqlServer
Microsoft.EntityFrameworkCore.Tools
接下来，创建一个数据库上下文类，用于定义实体类和数据库连接配置。在项目中创建一个名为AppDbContext.cs的文件，并添加以下代码：

using Microsoft.EntityFrameworkCore;namespace EFCoreDemo.Models
{public class AppDbContext : DbContext{public AppDbContext(DbContextOptions<AppDbContext> options) : base(options){}public DbSet<Customer> Customers { get; set; }}
}

然后，创建一个实体类来表示数据库表。在项目中创建一个名为Customer.cs的文件，并添加以下代码：

namespace EFCoreDemo.Models
{public class Customer{public int Id { get; set; }public string Name { get; set; }public string Email { get; set; }}
}

接下来，配置数据库连接。打开appsettings.json文件，并添加以下内容：

{"ConnectionStrings": {"DefaultConnection": "Server=(localdb)\\mssqllocaldb;Database=EFCoreDemo;Trusted_Connection=True;MultipleActiveResultSets=true"},"Logging": {"LogLevel": {"Default": "Information","Microsoft": "Warning","Microsoft.Hosting.Lifetime": "Information"}},"AllowedHosts": "*"
}

然后，在Startup.cs文件的ConfigureServices方法中添加以下代码，用于配置数据库上下文的依赖注入：

services.AddDbContext<AppDbContext>(options =>options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));

接下来，创建一个控制器类来处理增删改查操作。在项目中创建一个名为CustomersController.cs的文件，并添加以下代码：

using EFCoreDemo.Models;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using System.Collections.Generic;
using System.Threading.Tasks;namespace EFCoreDemo.Controllers
{[ApiController][Route("api/[controller]")]public class CustomersController : ControllerBase{private readonly AppDbContext _dbContext;public CustomersController(AppDbContext dbContext){_dbContext = dbContext;}[HttpGet]public async Task<ActionResult<IEnumerable<Customer>>> GetCustomers(){return await _dbContext.Customers.ToListAsync();}[HttpGet("{id}")]public async Task<ActionResult<Customer>> GetCustomer(int id){var customer = await _dbContext.Customers.FindAsync(id);if (customer == null){return NotFound();}return customer;}[HttpPost]public async Task<ActionResult<Customer>> CreateCustomer(Customer customer){_dbContext.Customers.Add(customer);await _dbContext.SaveChangesAsync();return CreatedAtAction(nameof(GetCustomer), new { id = customer.Id }, customer);}[HttpPut("{id}")]public async Task<IActionResult> UpdateCustomer(int id, Customer customer){if (id != customer.Id){return BadRequest();}_dbContext.Entry(customer).State = EntityState.Modified;try{await _dbContext.SaveChangesAsync();}catch (DbUpdateConcurrencyException){if (!_dbContext.Customers.Any(c => c.Id == id)){return NotFound();}else{throw;}}return NoContent();}[HttpDelete("{id}")]public async Task<IActionResult> DeleteCustomer(int id){var customer = await _dbContext.Customers.FindAsync(id);if (customer == null){return NotFound();}_dbContext.Customers.Remove(customer);await _dbContext.SaveChangesAsync();return NoContent();}}
}

最后，运行应用程序，并使用工具（例如Postman）测试增删改查操作。以下是一些示例请求的URL和请求体：

GET /api/customers：获取所有客户
GET /api/customers/{id}：根据ID获取客户
POST /api/customers：创建客户 请求体：
json
{
“name”: “John Doe”,
“email”: “john@example.com”
}
PUT /api/customers/{id}：更新客户 请求体：
json
{
“id”: 1,
“name”: “John Doe”,
“email”: “john.doe@example.com”
}
DELETE /api/customers/{id}：删除客户
希望这个示例能帮助你开始使用ASP.NET Core 6.0和Entity Framework Core进行增删改查操作。