c# - 在 MVC Core 3.1 中显示最后一条 Sql 记录

Question

我是 MVC Core 的新手，我在新闻网站项目上工作，我如何在我的索引上显示最后一条 SQL 记录？请详细描述，我应该在控制器和剃须刀页面上写什么？谢谢你

标签： c#asp.net-mvcmodel-view-controller.net-coreweb-development-server

Answer 1

    public class mycontroller:BaseController
    {  
       private readonly IRepo repo;

       public mycontroller(IRepo _repo)
       {
         _repo=repo;
       }
       [httpGet]
       public IActionResult<string> GetLastRecord()
       {
         return _repo.GetLastRecord();
       }
    }

       public class repo
       {
          private readonly IDBContextFactory dBContextFactory; 
          public repo(IDBContextFactory _dbContextFactory) 
          {
               _dbContextFactory=dBContextFactory;
          }
          public string GetLastRecord()
          {
               return _dbContextFactory.Select("mydb","select top 1 text from mydb order by  autoincreamentedkeyusualyid desc")[0];/* this is bad way of using data table I recommend using this https://stackoverflow.com/questions/33515552/converting-datatable-to-listentity-projectdracula */;
          }
       }
       public interface IRepo
       { 
          public string GetLastRecord();
       }
       public class DBContextFactory
       {
           private SqlCommand BuildFactory(string dbName)
           { 
                switch(dbName)
                {
                    case 'mydb':
                      return CreateMyDB();
                }
           }
           private SqlCommand CreateMyDB()
           { 
              string connectionString = "your connection string";
              SqlConnection connection =
                new SqlConnection(connectionString));

                SqlCommand command = new SqlCommand(connection);
                return command.Open();

           }
           //Private SqlCommand GetMyOpenCommand()
           public DataTable Select(string dbName,string query)
           {


                   SqlDataAdapter dataAdapter=new SqlDataAdapter();
                   dataAdapter.SelectCommand=BuildFactory(dbName);
                   DataSet dataSet=new DataSet();
                   dataAdapter.Fill(dataSet);
                   con.Close();
           }

       }
  public inteface IDBContextFactory
  { 
     SqlCommand BuildFactory(string dbName);
     SqlCommand CreateMyDB();
     DataTable Select(string dbName,string query)