使用列表从数据库接收行 [英] Using a list to receive rows from a database

问题描述

我尝试填充列表，而数据库连接，我已经得到了我的MVVM正确，但我不知道如何定义一个列表，然后在该列表中，连接到一个数据库并填充字段。任何人可以帮助？我的数据库很好用...

UserRepository

  public class UserRepository：IUserRepository 
 {
 
 private System.Data.SqlClient.SqlConnection connectionToDB; 
 
 private System.Data.SqlClient.SqlDataAdapter dataAdapter; 
 
 //获取由sqlStatement生成的数据集
 public System.Data.DataSet getDataSet（string sqlStatement）
 {
 System.Data.DataSet dataSet; 
 
 //创建对象dataAdapter以操作数据库中的表
 dataAdapter = new System.Data.SqlClient.SqlDataAdapter（sqlStatement，connectionToDB）; 
 
 //创建数据集
 dataSet = new System.Data.DataSet（）; 
 
 dataAdapter.Fill（dataSet）; 
 
 //返回dataSet 
 return dataSet; 
} 
 public List< Users> GetUsers（）
 {
 List< Users>用户; 
 
 
 //数据库连接以及列表填充
 //这样的东西吗？ 
 // 
 // new User 
 // ID = 
 // FirstName = 
 // LastName = 
 
 //用户= CollectionViewSource.GetDefaultView（_users）; 
 
 
 
返回用户; 
} 
 
 
} 
  

DBViewModel

  public class DBDisplayViewModel 
 {
 private ObservableCollection<用户>用户; 
 
 public DBDisplayViewModel（）
 {
 Load（）; 
} 
 
 public IUserRepository UserRepository 
 {
 get;组; 
} 
 
 public ObservableCollection< Users>用户
 {
 get 
 {
 if（users == null）
 {
 users = new ObservableCollection< Users>（）; 
} 
 
返回用户; 
} 
 set 
 {
 if（value！= null）
 {
 users = value; 
} 
} 
} 
 
 private void Load（）
 {
 List< Users> users = UserRepository.GetUsers（）; 
 Users = new ObservableCollection< Users>（users）; 
} 
} 
  

用户

这只是定义 ID FirstName LastName 属性

因此要分解：在 UserRepository 需要创建以拉入数据库连接和数据库值。任何人可以帮助？

解决方案

看看下面的代码，会给予想法

  public List< Users> GetUsers（）
 {
 List< Users> users = new List< Users> （）; 
 DataSet ds = getDataSet（Select FirstName，...... from Users）
用户用户; 
 
 foreach（ds.Tables [0] .Rows中的DataRow行）
 {
 user = new Users（）; 
 user.FirstName = row [firstname]。ToString（）; 
 .... 
 .... 
 users.Add（user）
} 
返回用户; 
} 
  




I am trying to populate a list whilst a database connection, I have gotten my MVVM down correctly, but I have no idea how to define a list, then in that list, connect to a db and populate the fields. Can anyone help? My database works fine...

UserRepository

public class UserRepository: IUserRepository
{

    private System.Data.SqlClient.SqlConnection connectionToDB;

    private System.Data.SqlClient.SqlDataAdapter dataAdapter;

    // Get the data set generated by the sqlStatement
    public System.Data.DataSet getDataSet(string sqlStatement)
    {
        System.Data.DataSet dataSet;

        // creates the object dataAdapter to manipulate a table from the database
        dataAdapter = new System.Data.SqlClient.SqlDataAdapter(sqlStatement, connectionToDB);

        // create the dataset
        dataSet = new System.Data.DataSet();

        dataAdapter.Fill(dataSet);

        //return the dataSet
        return dataSet;
    }
    public List<Users> GetUsers()
    {
        List<Users> users;


        // Database connection to go here along with the list population
        // Something like this?
        //
        // new User
        //     ID = 
        //     FirstName = 
        //     LastName =   

        //  Users = CollectionViewSource.GetDefaultView(_users);



        return users;
    }


}

DBViewModel

public class DBDisplayViewModel
{
    private ObservableCollection<Users> users;

    public DBDisplayViewModel()
    {
        Load();
    }

    public IUserRepository UserRepository
    {
        get; set;
    }

    public ObservableCollection<Users> Users
    {
        get
        {
            if (users == null)
            {
                users = new ObservableCollection<Users>();
            }

            return users;
        }
        set
        {
            if (value != null)
            {
                users = value;
            }
        }
    }

    private void Load()
    {
        List<Users> users= UserRepository.GetUsers();
        Users= new ObservableCollection<Users>(users);
    }
}

Users

This just defines the ID FirstName LastName Properties

So to break it down: The information commented out in UserRepository needs to be created to pull in the database connection and the database values. Can anyone help? Much love!

解决方案

Look at the below code, will give idea

        public List<Users> GetUsers()
            {
                List<Users> users=new  List<Users> ();
                DataSet ds=getDataSet("Select FirstName,...... from Users")
                Users user;

                 foreach(DataRow row in ds.Tables[0].Rows)
                 {
                   user=new Users();
                   user.FirstName=row["firstname"].ToString();
                    ....
                    ....
                   users.Add(user)
                 }
                return users;
            }

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