[英]How do I use constructer for a class with a class as a field in C# Entity Framework Core?
我剛剛開始使用 C# 中的實體框架核心,我正在嘗試設置一個 class 結構,其中一個 class 有一個字段是另一個 class 我發現,當類沒有構造函數時,代碼運行良好。 但是,當我按如下方式引入構造函數時:
public class InterestEF
{
public InterestEF(string id, int numTimesInterestSelected, AdminEditEF lastEdit, ICollection<AdminEditEF> allEdits)
{
this.id = id;
this.numTimesInterestSelected = numTimesInterestSelected;
this.lastEdit = lastEdit;
this.allEdits = allEdits;
}
[Key]
public string id { get; set; }
public int numTimesInterestSelected { get; set; }
public AdminEditEF lastEdit { get; set; }
public virtual ICollection<AdminEditEF> allEdits { get; set; }
}
public class AdminEditEF
{
public AdminEditEF(string id, string adminIdEditedBy, DateTime dateEdited, string changesMade, string reasonsForChanges, string idOfEditedEntity, EntityTypeEdited entityTypeEdited)
{
this.id = id;
AdminIdEditedBy = adminIdEditedBy;
this.dateEdited = dateEdited;
this.changesMade = changesMade;
this.reasonsForChanges = reasonsForChanges;
this.idOfEditedEntity = idOfEditedEntity;
this.entityTypeEdited = entityTypeEdited;
}
[Key]
public string id { get; set; }
public string AdminIdEditedBy { get; set; }
public DateTime dateEdited { get; set; }
public string changesMade { get; set; }
public string reasonsForChanges { get; set; }
public string idOfEditedEntity { get; set; }
public EntityTypeEdited entityTypeEdited { get; set; }
}
public class MySQLEFContext : DbContext
{
public DbSet<AdminEditEF> AdminEdits { get; set; }
public DbSet<InterestEF> interests { get; set; }
public MySQLEFContext(DbContextOptions<MySQLEFContext> options): base(options) { }
}
我收到以下錯誤:
System.InvalidOperationException: 'No suitable constructor found for entity type 'InterestEF'. The following constructors had parameters that could not be bound to properties of the entity type: cannot bind 'lastEdit' in 'InterestEF(string id, int numTimesInterestSelected, AdminEdit lastEdit)'.'
基本上,我只是想知道是否有可能擁有一個具有類作為字段的 class,它還具有一組帶有參數的構造函數,我可以在代碼中的其他地方調用?
任何幫助將不勝感激。 非常感謝您的閱讀!
從 文檔:
- EF Core 無法使用構造函數設置導航屬性(例如上面的博客或帖子)。
因此,您需要一個如下所示的構造函數:
public InterestEF(string id, int numTimesInterestSelected)
{
this.id = id;
this.numTimesInterestSelected = numTimesInterestSelected;
}
或無參數的:
public InterestEF()
{
}
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