c# – 如何在EF中指定左连接？

概述我的模特： public partial class history_builds{ public int ID { get; set; } public int build { get; set; } public int br { get; set; } public int tag { get; set; } public string line { 我的模特：

public partial class history_builds{    public int ID { get; set; }    public int build { get; set; }    public int br { get; set; }    public int tag { get; set; }    public string line { get; set; }    public int rev { get; set; }    public int user_ID { get; set; }    public string distrib_path { get; set; }    public string setup_path { get; set; }    public System.DateTime build_date { get; set; }    public string product { get; set; }}public partial class history_uploads{    public int ID { get; set; }    public int ID_user { get; set; }    public string line { get; set; }    public int Build { get; set; }    public string distrib { get; set; }    public System.DateTime Time_upload { get; set; }    public int Status { get; set; }}public partial class user{    public int ID { get; set; }    public string name { get; set; }    public int ID_group { get; set; }}

语境：

public DbSet<history_builds> history_builds { get; set; }public DbSet<history_uploads> history_uploads { get; set; }public DbSet<user> users { get; set; }

我试着做这个Entity framework left join的左连接

var items = entitIEs.history_builds    .Join(        entitIEs.users.DefaultIfEmpty(),hb => hb.user_ID,u => u.ID,(hb,u) =>            new {                hb.distrib_path,hb.setup_path,hb.build_date,hb.build,User = (u == null ? String.Empty : u.name),hb.rev            }    )    .Join(entitIEs.history_uploads.DefaultIfEmpty(),hb => hb.build,hu => hu.Build,hu) =>            new HistoryBuIDItem {                Revision = hb.rev,Build = hb.build,distribPath = hb.distrib_path,SetupPath = hb.setup_path,BuildDate = hb.build_date,User = hb.User,Isupload = (hu == null ? true : false)            }    )    .Where(x => IDs.Contains(x.Revision))    .ToList();

但它不起作用,EF仍然发出内连接sql代码,有什么问题？

解决方法 左外连接示例：

from c in table0join o in table1 on c.sno equals o.sno into psfrom o in ps.DefaultIfEmpty()select new { c.name,o.number}

它渲染sql：

SELECT [t0].[name],[t1].[number] AS [number]FROM [table0] AS [t0]left OUTER JOIN [table1] AS [t1] ON ([t0].[sno]) = [t1].[sno]

总结

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