c# WebApi 数据库连接(EF框架)

1.EF框架包：

安装EF框架包:
Microsoft.EntityFrameworkCore
Microsoft.EntityFrameworkCore.SqlSeerver
Microsoft.EntityFrameworkCore.Tools
Microsoft.EntityFrameworkCore.Design

2.创建数据库

数据表

CREATE table base_user (
id int IDENTITY(1,1) PRIMARY KEY not null
,t_name VARCHAR(50) not null
,t_city VARCHAR(50) 
,t_money int
)

3.利用框架包连接数据库

在VS中视图选择程序包管理器控制台,输入命令:(Scaffold-DbContext -Force “Server=.;Database=…;uid=…;Password=…;” Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models -Context WebApiContext)(将等号后面的值换作自己的数据库信息值)
命令执行完成后,EF框架会自动生成与数据表相对应的实体类.

4.数据处理

[ApiController]
[Route("user")]
puliic class BaseUserController:ControllerBase{
    
    
        /// <summary>
        /// 登录
        /// </summary>
        /// <param name="account">包括：账号/手机号/邮箱</param>
        /// <param name="pwd">密码</param>
        /// <returns></returns>
        [HttpGet("login")]
        public WebApiResponse Login(string account, string pwd)
        {
    
    
            WebApiContext context = null;
            try
            {
    
    
                context = new WebApiContext();
                BaseUser user = context.BaseUsers.FirstOrDefault(x => (x.TCode == account || x.TPhone == account || x.TEmail == account) && x.TPwd == pwd);
                if(user == null)
                {
    
    
                    return WebApiResponse.Create(2, "账号或密码错误");
                }
                user.TPwd = null;
                string token = Guid.NewGuid().ToString().Replace("-", "");
                UserData.AddToken(token, user.Id);
                Dictionary<string, object> data = new Dictionary<string, object>()
                {
    
    
                    ["user"] = user,
                    ["token"] = token
                };
                return WebApiResponse.OK(data);
            }
            catch (Exception ex)
            {
    
    
                return WebApiResponse.Create(1, "服务器异常");
            }
        }
        [HttpGet("selectById")]
        public WebApiResponse SeleteById(string token, int id)
        {
    
    
            BaseUser user = UserData.GetUserById(id);
            if (user == null)
            {
    
    
                return WebApiResponse.Create(1, "未查询到数据");
            }
            return WebApiResponse.OK(user);
        }

        /// <summary>
        /// 修改（会有问题，容易产生数据库和缓存不一致的情况）
        /// </summary>
        /// <returns></returns>
        [HttpPost("edit1")]
        public WebApiResponse Edit1(string token, BaseUserEditDto dto)
        {
    
    
            //当修改的时候，先删除缓存数据，再修改数据库，再次删除缓存数据
            BaseUser user = UserData.GetUserById(dto.Id);
            if (user == null)
            {
    
    
                return WebApiResponse.Create(2, "数据不存在");
            }
            WebApiContext context = null;

            try
            {
    
    
                context = new WebApiContext();
                user.TName = dto.TName;
                user.TCity = dto.TCity;
                user.TStatus = dto.TStatus;
                user.TEmail = dto.TEmail;
                user.TPhone = dto.TPhone;
                context.BaseUsers.Update(user);
                context.SaveChanges();
            }
            catch (Exception)
            {
    
    
                return WebApiResponse.Create(1, "服务器异常");
            }
            finally
            {
    
    
                context?.Dispose();
            }
            return WebApiResponse.OK("修改成功");
        }

 /// <summary>
        /// 修改
        /// </summary>
        /// <returns></returns>
        [HttpPost("edit")]
        public WebApiResponse Edit(string token, BaseUserEditDto dto)
        {
    
    
            //当修改的时候，先删除缓存数据，再修改数据库，再次删除缓存数据
            WebApiContext context = null;
            try
            {
    
    
                //先删除缓存数据
                UserData.RemoveUserById(dto.Id);
                context = new WebApiContext();
                //再修改数据库
                BaseUser user = context.BaseUsers.FirstOrDefault(x => x.Id == dto.Id);
                if (user == null)
                {
    
    
                    return WebApiResponse.Create(2, "数据不存在");
                }
                user.TName = dto.TName;
                user.TCity = dto.TCity;
                user.TStatus = dto.TStatus;
                user.TEmail = dto.TEmail;
                user.TPhone = dto.TPhone;
                context.BaseUsers.Update(user);
                context.SaveChanges();
                //再次删除缓存数据
                UserData.RemoveUserById(dto.Id);
            }
            catch (Exception)
            {
    
    
                return WebApiResponse.Create(1, "服务器异常");
            }
            finally
            {
    
    
                context?.Dispose();
            }
            return WebApiResponse.OK("修改成功");
        }

        [HttpDelete("delete")]
        public WebApiResponse Delete(string token, int id)
        {
    
    
            WebApiContext context = null;
            try
            {
    
    
                context = new WebApiContext();
                BaseUser user = context.BaseUsers.FirstOrDefault(x => x.Id == id);
                if (user == null)
                {
    
    
                    return WebApiResponse.Create(2, "数据不存在");
                }
                context.BaseUsers.Remove(user);
                context.SaveChanges();
                //从缓存中删除
                UserData.RemoveUserById(user.Id);
                return WebApiResponse.OK();
            }
            catch (Exception)
            {
    
    
                return WebApiResponse.Create(1, "服务器异常");
            }
            finally
            {
    
    
                context?.Dispose();
            }
        }
}