DbUpdateException 同时使用 LINQ to Database 更新记录

Question

我一直在尝试以 window 形式更新数据库中的记录，但每次单击更新按钮时都会出现此错误。

System.Data.Entity.Infrastructure.DbUpdateException: 'An error occurred while updating the entries. See the inner exception for details.' SqlException: Violation of PRIMARY KEY constraint 'PK_ad_gb_rsm'. Cannot insert duplicate key in object 'dbo.ad_gb_rsm'. The duplicate key value is (100001). The statement has been terminated.

下面是我使用的 LINQ 代码

private void btu_Update_Click(object sender, EventArgs e)
{
    if (radioButtonMale.Checked)
    {
        gender = "male";
    }
    else if (radioButtonFemale.Checked)
    {
        gender = "female";
    }
    userID = Convert.ToDecimal(txtUserID.Text);
   
    //ad_gb_rsm acc = DBS.ad_gb_rsm.First(s => s.ICube_id.Equals(userID));

    var query = (from upd in DBS.ad_gb_rsm where upd.ICube_id == userID select upd).ToList();
    foreach (var acc in query)
    {
        acc.user_type = comboBoxUser_Type.Text;
        acc.JDate = dateTimeCrtDate.Text;
        acc.title = comboBoxTitle.Text;
        acc.fName = txtFname.Text;
        acc.mName = txtMName.Text;
        acc.lName = txtLName.Text;
        acc.DOB = dateTimeDOB.Value.ToString();
        acc.Gender = gender;
        acc.Phone = txtPhoneNumber.Text;
        acc.zip_code = txtZipCode.Text;
        acc.POB = txtPOBAddress.Text;
        acc.address = txtAddress.Text;
        acc.email = txtEmail.Text;
        acc.City = txtCity.Text;
        acc.State = txtState.Text;
        acc.marrital_Status = comboBoxMS.Text;
        acc.NOK_Name = txtNKName.Text;
        acc.NOK_Phone = txtNKNumber.Text;
        acc.NOK_Address = txtNOKAddress.Text;
        acc.NOKRela = txtNOKRela.Text;
        acc.create_dt = dateTimeCrtDate.Value.ToString();

        Image img = LogUserImage.Image;
        if (img.RawFormat != null)
        {
            if (ms != null)
            {
                img.Save(ms, img.RawFormat);
                acc.Picture = ms.ToArray();
            }
        }
        acc.Dept_Sector = comboBoxDeptSector.Text;
        acc.Position = comboBoxPosition.Text;
        acc.JDate = dateTimeJoinDt.Value.ToString();
        acc.Empl_Status = comboBoxUserStatus.Text;
        acc.username = txtUsername.Text;
        acc.password = txtPassword.Text;
        acc.incu_copany_name = txtIncu_CompanyName.Text;
        acc.createdBy = AdministratorBankLogin.AdminUserLogin.Username;
        try
        {
            DBS.ad_gb_rsm.Add(acc);
            DBS.SaveChanges();
            MessageBox.Show("User Created Successfully");
        }
        catch (Exception exception)
        {
            Console.WriteLine(exception);
            throw;
        }
    }
}

我不知道我做错了什么。我是新手。

Answer 1

内部异常说明一切：

SqlException: Violation of PRIMARY KEY constraint 'PK_ad_gb_rsm'. Cannot insert duplicate key in object 'dbo.ad_gb_rsm'. The duplicate key value is (100001)

您的代码试图执行 INSERT 操作，但失败了，因为它违反了主键的唯一约束。

问题的根本原因是以下行：

DBS.ad_gb_rsm.Add(acc);

因为 Add 调用您的 acc 实体的 state 变成 Added 而不是 Modified。如果您删除 Add 方法调用，那么它将将该实体视为 Modified 并将执行 UPDATE 操作。

如果您不熟悉此更改跟踪概念，请阅读 this MDSN article。

DbUpdateException 同时使用 LINQ to Database 更新记录

DbUpdateException Whiles updating record using LINQ to Database

c#

linq

linq-to-sql