如何在更新密码时插入日期？

Question

您可以查看我的PICT： My relationship picture

 entities = new sampleEntities(); 
     User usr = (from i in entities.Users 
        join j in entities.Updates 
        on i.ID equals j.ID 
        where i.NAME == name 
        select i).First(); 

     usr.PASSWORD = textBox2.Text; 
     entities.SaveChanges(); 

所以，当我更新密码，如何使我的更新时间也进入

Answer 1

您可以覆盖的SaveChanges。

public override int SaveChanges() 
{ 

    var addedUsers = ChangeTracker.Entries<User>().Where(x => x.State 
             == EntityState.Added).ToList(); 

    addedUsers.ForEach(x => 
    { 
     x.Update = new Update{DateOfUpdate = DateTime.Now} 
    }); 

    var modifiedUsers = ChangeTracker.Entries<User>().Where(x => x.State 
              == EntityState.Modified).ToList(); 

    modifiedUsers.ForEach(x => 
    { 
     x.Update.DateOfUpdate = DateTime.Now; 
    }); 

    return base.SaveChanges(); 
} 

如果您打算跟踪这些修改日期为多个表更好地使用这些日期的基类，并继承需要从此类修改日期的所有表。这样，saveChanges覆盖将是通用的，并适用于从该基类继承的所有表。

Answer 2

如果你只需要更新Date of Update你可以改变选择也把这个数据反馈，然后更新User和Update表

entities = new sampleEntities(); 
var data = (from i in entities.Users 
       join j in entities.Updates 
       on i.ID equals j.ID 
       where i.NAME == name 
       select new {user = i, update = j).First(); 

    data.user.PASSWORD = textBox2.Text; 
    if (data.update == null) data.update = new Update(); 

    data.update.DateofUpdate = DateTime.Now; 
    entities.SaveChanges();