连接两个表实体框架

Posted 2023-04-12

【中文标题】连接两个表实体框架

【英文标题】：Joining two tables entity framework

【发布时间】：2017-01-29 18:07:09

【问题描述】：

我正在尝试使用 LINQ 连接实体框架中的两个表

以下是型号：

    public partial class PredbiljezbeEF
    
        public int idPredbiljezba  get; set; 
        public Nullable<System.DateTime> datumPredbiljezba  get; set; 
        public string imePolaznik  get; set; 
        public string prezimePolaznik  get; set; 
        public string gradPolaznik  get; set; 
        public string adresaPolaznik  get; set; 
        public Nullable<int> postanskiBrojPolaznik  get; set; 
        public Nullable<bool> statusPredbiljezba  get; set; 
        public int idSeminar  get; set; 

        public virtual SeminariEF SeminariEF  get; set; 
    

        public partial class SeminariEF
    

        public SeminariEF()
        
            this.PredbiljezbeEFs = new HashSet<PredbiljezbeEF>();
        

        public int idSeminar  get; set; 
        public string nazivSeminar  get; set; 
        public string opisSeminar  get; set; 
        public string datumSeminar  get; set; 
        public Nullable<bool> statusSeminar  get; set; 
        public Nullable<int> brojPredbiljezbi  get; set; 

这是 LINQ 表达式：

        if(!IsPostBack)
        
            SeminariEntities db = new SeminariEntities();

            var predB = (from x in db.PredbiljezbeEFs
                         join y in db.SeminariEFs on x.idSeminar equals y.idSeminar
                         select new
                         
                             id = x.idPredbiljezba,
                             ime = x.imePolaznik,
                             prez = x.prezimePolaznik,
                             datum = x.datumPredbiljezba,
                             grad = x.gradPolaznik,
                             adresa = x.adresaPolaznik,
                             post = x.postanskiBrojPolaznik,
                             status = x.statusPredbiljezba,
                             naziv = y.nazivSeminar,
                             datumS = y.datumSeminar

                         ).ToList();







            //var predB = (from x in db.PredbiljezbeEFs select x).ToList();

            gvPredbiljezbe.DataSource = predB.ToList();
            gvPredbiljezbe.DataBind();


        

我收到此错误：

DataBinding: 'f__AnonymousType010[[System.Int32, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.Nullable1[[System.DateTime, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken =b77a5c561934e089]，[System.String，mscorlib，版本=4.0.0.0，Culture=neutral，PublicKeyToken=b77a5c561934e089]，[System.String，mscorlib，版本=4.0.0.0，Culture=neutral，PublicKeyToken=b77a5c561934e089]，[System .Nullable1[[System.Int32, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.Nullable1[[System.Boolean, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]], mscorlib, Version=4.0.0.0, Culture=n...' 不包含属性名为“idPredbiljezba”。

有人可以帮忙吗。

【问题讨论】：

能否分享一下GridView的代码？

为什么加入？别。你有一个导航属性PredbiljezbeEF.SeminariEF。

我想过，但我不是很熟悉。你能写一些在这种情况下如何使用它的例子吗？

使用导航属性

嗯，x.SeminariEF.nazivSeminar 等

【参考方案1】：

从异常message => something（可能是数据网格？）试图从您的gvPredbiljezbedataSource 访问名称为[idPredbiljezba] 的属性，但查询最终投影不包含您投影属性@987654325 的此类属性@如[id]

希望对你有帮助