Question

我想在SQL数据网格中显示此WPF查询的结果。我的问题如何使用EF6运行此查询？

select c.*, count(o.id) from clients c
left join optics o
on o.client_id = c.id
where o.r_sph = 12 // 12 is a variable value
group by c.id

我的客户模型：

    public clients()
    {
        this.optics = new ObservableCollection<optics>();
    }

    public long id { get; set; }
    public string name { get; set; }
    public string phone { get; set; }
    public Nullable<System.DateTime> date_of_birth { get; set; }
    public System.DateTime inserted_at { get; set; }
    public System.DateTime updated_at { get; set; }


    public virtual ObservableCollection<optics> optics { get; set; }

和光学模型：

    public long id { get; set; }
    public Nullable<System.DateTime> at { get; set; }
    public Nullable<decimal> r_sph { get; set; }
    public Nullable<int> r_axs { get; set; }
    public string notes { get; set; }
    public Nullable<long> client_id { get; set; }
    public System.DateTime inserted_at { get; set; }
    public System.DateTime updated_at { get; set; }

    public virtual clients clients { get; set; }

更新

我使用此代码过滤结果：

public IQueryable < Multi.Model.clients > FilterClients(optisysEntities db, System.Linq.IQueryable < Multi.Model.clients > clients, ClientsFilter clientsFilter) {

 if (!String.IsNullOrWhiteSpace(clientsFilter.Name))
  clients = db.clients.Where(c => c.name.Contains(clientsFilter.Name));

 if (!String.IsNullOrWhiteSpace(clientsFilter.Phone))
  clients = clients.Where(u => u.phone.Contains(clientsFilter.Phone));

}

Answer 1

您需要返回一个新对象（除非您已经有一个包含“Count”属性的模型设置）。像这样：

var query = (from c in context.Clients
             join o in context.Optics
               on c.id equals o.client_id
            where o.r_sph == 12
            group new { c, o } by new { c.Id } 
             into g
           select new {Id = g.Key.id,
                       // other properties from "Client",
                       Count = g.Count()}
            ).ToList();

如何使用Entity Framework 6中的count和join编写此SQL语句

1 个答案: