使用实体框架更新一条记录

Question

我想使用 entity framework 将一条记录更新到数据库。当更新此员工的所有日期的记录时，设置 Null Only Employee Code And IsActive .. 如何仅更新 isActive

这是我的代码

       private void btn_Save_Resignation_Click(object sender, EventArgs e)
       {
          try
           {
                   var IsActive = new database.tblEmployeeData
                   {

                       EmployeeCode = Convert.ToInt32(txtEmpCode.Text),
                       IsActive = cbxResignationEmp.Checked = true, 
                   };


                       db.tblEmployeeDatas.AddOrUpdate(IsActive);
                       db.SaveChanges();
                       MessageBox.Show("تم إقالة الموظف بنجاح", "Sigma Software", MessageBoxButtons.OK, MessageBoxIcon.Information);
                       ClearResignation();

           }
           catch (Exception ex)
           {
               MessageBox.Show(ex.Message, "Sigma Software", MessageBoxButtons.OK, MessageBoxIcon.Information);
           }
}

................. 这是我的模特class

   public partial class tblEmployeeData
   {
       [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
       public tblEmployeeData()
       {
           this.tblBlackListForEmps = new HashSet<tblBlackListForEmp>();
           this.tblContractForEmploees = new HashSet<tblContractForEmploee>();
           this.tblCustodyForEmps = new HashSet<tblCustodyForEmp>();
           this.tblDocumentEmployeeWithStates = new HashSet<tblDocumentEmployeeWithState>();
           this.tblOtherDataForEmps = new HashSet<tblOtherDataForEmp>();
           this.tblPenaltyForEmployees = new HashSet<tblPenaltyForEmployee>();
       }

       public int EmployeeCode { get; set; }
       public string EmployeeName { get; set; }
       public Nullable<byte> GenderCode { get; set; }
       public Nullable<byte> PranchCode { get; set; }
       public Nullable<byte> RelationShipCode { get; set; }
       public Nullable<byte> AdministrationCode { get; set; }
       public Nullable<byte> DepartmentCode { get; set; }
       public Nullable<short> JopCode { get; set; }
       public Nullable<byte> JopLevelCode { get; set; }
       public Nullable<byte> ConCustmerCode { get; set; }
       public Nullable<byte> NationalityCode { get; set; }
       public Nullable<byte> TypeOfWorkersCode { get; set; }
       public Nullable<bool> IsActive { get; set; }

Answer 1

正如解释的那样here：

Entity Framework does not magically figure out which properties have changed vs. which properties have not changed, it takes the entity, and if it exists, enters the entity into the database as it’s currently populated. If the entity does not exist, it inserts it into the database.

所以我建议您按以下方式更改代码：

var empCode = Convert.ToInt32(txtEmpCode.Text);
var IsActive = db.tblEmployeeDatas.FirstOrDefault(e => e.EmployeeCode == empCode);
if (IsActive == null)
{
   IsActive = new database.tblEmployeeData
   {
      EmployeeCode = empCode,
   };
}
IsActive.IsActive = cbxResignationEmp.Checked = true, // BTW should it be assigning or condition?

db.tblEmployeeDatas.AddOrUpdate(IsActive);
db.SaveChanges();
...

使用实体框架更新一条记录

Update one record using entity frame work

c#

entity-framework

insert-update