所有 CRUD 操作均有效，但更新/编辑除外。我正在使用柚子，因为我正在使用Mysql。对于面临的问题，我正在使用相同的创建表单来编辑数据，但是当我尝试编辑时会引发异常。
这是例外：
失败：Microsoft.EntityFrameworkCore.Update [10000]
保存上下文类型为“ ICFERApp.Data.ApplicationDbContext”的更改时，数据库中发生了异常。Microsoft.EntityFrameworkCore.DbUpdateException：更新条目时发生错误。有关详细信息，请参见内部异常。
MySql.Data.MySqlClient.MySqlException：键'IX_Education_StudentId'的条目'3'重复
MySql.Data.MySqlClient.MySqlException：项“ IX_Education_StudentId”的条目“ 3”重复
在MySqlConnector.Core.ResultSet.ReadResultSetHeaderAsync（IOBehavior ioBehavior）在C：\ projects \ mysqlconnector \ src \ MySqlConnector \ Core \ ResultSet.cs：行43
---内部异常堆栈跟踪的结尾---
在MySql.Data.MySqlClient.MySqlDataReader.ActivateResultSet（ResultSet resultSet）在C：\ projects \ mysqlconnector \ src \ MySqlConnector \ MySql.Data.MySqlClient \ MySqlDataReader.cs：line 81
在MySql.Data.MySqlClient.MySqlDataReader.ReadFirstResultSetAsync（IOBehavior ioBehavior）在C：\ projects \ mysqlconnector \ src \ MySqlConnector \ MySql.Data.MySqlClient \ MySqlDataReader.cs：line 307
这些是我的模型类：
public class Student
{
[Key]
public long Id { get; set; }
[Display(Name="First Name")]
public string FirstName { get; set; }
[Display(Name="Middle Name")]
public string MiddleName { get; set; }
[Display(Name="Last Name")]
public string LastName { get; set; }
[Display(Name="Nationality")]
public string Nationality { get; set; }
[Display(Name="Gender")]
public string Gender { get; set; }
[Display(Name="Religion")]
public string Religion { get; set; }
[Display(Name="Medical Condition")]
public string MedicalCondition { get; set; }
[Display(Name="Deceased")]
public string Deceased { get; set; }
[Display(Name="Home Address")]
public string HomeAddress { get; set; }
[Display(Name="Country Of Residence")]
public string CountryOfResidence { get; set; }
[Display(Name="City")]
public string City { get; set; }
[Display(Name="Date Of Birth")]
public DateTime DateOfBirth { get; set; }
public int Age { get; set; }
public virtual Parents Parents { get; set; }
public virtual Education Education { get; set; }
}
public class Parents
{
public long Id { get; set; }
[Display(Name="Religion Of Deceased Father")]
public string ReligionOfDeceasedFather { get; set; }
[Display(Name="Religion Of Deceased Mother")]
public string ReligionOfDeceasedMother { get; set; }
[Display(Name="Date Of Demise Father")]
[DisplayFormat(DataFormatString = "{0:dd.MM.yyyy}")]
public DateTime DateOfDemiseOfFather { get; set; }
[Display(Name="Date Of Demise Mother")]
[DisplayFormat(DataFormatString = "{0:dd.MM.yyyy}")]
public DateTime DateOfDemiseOfMother { get; set; }
[Display(Name="Names of Mother")]
public string NamesOfMother { get; set; }
[Display(Name="Names of Father")]
public string NamesOfFather { get; set; }
[Display(Name="Religion of Mother")]
public string ReligionOfMother { get; set; }
[Display(Name="Marital Status of Mother")]
public string MaritalStatusOfMother { get; set; }
[Display(Name="Occupation of Mother")]
public string OccupationOfMother { get; set; }
[Display(Name="Monthly Income")]
public double MonthlyIncome { get; set; }
public virtual Student Student { get; set; }
public long? StudentId { get; set; }
}
public class Education
{
public long Id { get; set; }
[Display(Name="Education Level")]
public string EducationLevel { get; set; }
[Display(Name="School")]
public string School { get; set; }
[Display(Name="Address of School")]
public string AddressOfSchool { get; set; }
[Display(Name="Head Teacher")]
public string HeadTeacher { get; set; }
[Display(Name="Telephone")]
public string Telephone { get; set; }
public virtual Student Student { get; set; }
public long? StudentId { get; set; }
}
我的问题是为什么我不能使用Entity Framework Core自动更新？
这些是负责在我的 Controller 类中进行编辑的方法：
[HttpPost]
public IActionResult New(Student student, string IsEditMode)
{
if (!ModelState.IsValid)
{
ViewBag.IsEditMode = IsEditMode;
return View(student);
}
try
{
if (IsEditMode.Equals("false"))
{
_studentRepository.Create(student);
}
else
{
_studentRepository.Edit(student);
}
return RedirectToAction(nameof(Index));
}
catch (Exception e)
{
return RedirectToAction(nameof(Index));
}
}
public IActionResult Edit(int id)
{
try
{
ViewBag.IsEditMode = "true";
var student = _studentRepository.GetSingleStudent(id);
return View("New", student);
}
catch (Exception ex)
{
return Content("Could not find Pet");
}
}
然后，在我的Repository类中，这是 Edit 方法：
public void Edit(Student student)
{
_context.Students.Update(student);
_context.SaveChanges();
}
我将非常感谢您提供有关此阻止程序的帮助。谢谢。
编辑
这是我的表单，可以处理创建和编辑。
@model Student
<form asp-action="New" method="Post" asp-controller="Student">
<div asp-validation-summary="All"></div>
<input asp-for="Id" type="hidden"/>
<input name="IsEditMode" id="IsEditMode" value="@ViewBag.IsEditMode" type="hidden"/>
<div class="form-row">
<div class="col">
<label asp-for="FirstName"></label>
<input asp-for="FirstName" class="form-control"/>
<span asp-validation-for="FirstName" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="MiddleName"></label>
<input asp-for="MiddleName" class="form-control"/>
<span asp-validation-for="MiddleName" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="LastName"></label>
<input asp-for="LastName" class="form-control"/>
<span asp-validation-for="LastName" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Nationality"></label>
<input asp-for="Nationality" class="form-control"/>
<span asp-validation-for="Nationality" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="Gender"></label>
<input asp-for="Gender" class="form-control"/>
<span asp-validation-for="Gender" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Religion"></label>
<input asp-for="Religion" class="form-control"/>
<span asp-validation-for="Religion" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="MedicalCondition"></label>
<input asp-for="MedicalCondition" class="form-control"/>
<span asp-validation-for="MedicalCondition" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Deceased"></label>
<input asp-for="Deceased" class="form-control"/>
<span asp-validation-for="Deceased" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="HomeAddress"></label>
<input asp-for="HomeAddress" class="form-control"/>
<span asp-validation-for="HomeAddress" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="CountryOfResidence"></label>
<input asp-for="CountryOfResidence" class="form-control"/>
<span asp-validation-for="CountryOfResidence" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="City"></label>
<input asp-for="City" class="form-control"/>
<span asp-validation-for="City" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="DateOfBirth"></label>
<input asp-for="DateOfBirth" class="form-control"/>
<span asp-validation-for="DateOfBirth" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="Parents.ReligionOfDeceasedFather"></label>
<input asp-for="Parents.ReligionOfDeceasedFather" class="form-control"/>
<span asp-validation-for="Parents.ReligionOfDeceasedFather" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Parents.ReligionOfDeceasedMother"></label>
<input asp-for="Parents.ReligionOfDeceasedMother" class="form-control"/>
<span asp-validation-for="Parents.ReligionOfDeceasedMother" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="Parents.DateOfDemiseOfFather"></label>
<input asp-for="Parents.DateOfDemiseOfFather" class="form-control"/>
<span asp-validation-for="Parents.DateOfDemiseOfFather" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Parents.DateOfDemiseOfMother"></label>
<input asp-for="Parents.DateOfDemiseOfMother" class="form-control"/>
<span asp-validation-for="Parents.DateOfDemiseOfMother" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="Parents.NamesOfMother"></label>
<input asp-for="Parents.NamesOfMother" class="form-control"/>
<span asp-validation-for="Parents.NamesOfMother" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Parents.NamesOfFather"></label>
<input asp-for="Parents.NamesOfFather" class="form-control"/>
<span asp-validation-for="Parents.NamesOfFather" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="Parents.ReligionOfMother"></label>
<input asp-for="Parents.ReligionOfMother" class="form-control"/>
<span asp-validation-for="Parents.ReligionOfMother" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Parents.MaritalStatusOfMother"></label>
<input asp-for="Parents.MaritalStatusOfMother" class="form-control"/>
<span asp-validation-for="Parents.MaritalStatusOfMother" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="Parents.OccupationOfMother"></label>
<input asp-for="Parents.OccupationOfMother" class="form-control"/>
<span asp-validation-for="Parents.OccupationOfMother" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Parents.MonthlyIncome"></label>
<input asp-for="Parents.MonthlyIncome" class="form-control"/>
<span asp-validation-for="Parents.MonthlyIncome" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="Guardian.FirstName"></label>
<input asp-for="Guardian.FirstName" class="form-control"/>
<span asp-validation-for="Guardian.FirstName" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Guardian.MiddleName"></label>
<input asp-for="Guardian.MiddleName" class="form-control"/>
<span asp-validation-for="Guardian.MiddleName" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="Guardian.LastName"></label>
<input asp-for="Guardian.LastName" class="form-control"/>
<span asp-validation-for="LastName" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Guardian.RelationshipToOrphan"></label>
<input asp-for="Guardian.RelationshipToOrphan" class="form-control"/>
<span asp-validation-for="Guardian.RelationshipToOrphan" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="Guardian.Occupation"></label>
<input asp-for="Guardian.Occupation" class="form-control"/>
<span asp-validation-for="Guardian.Occupation" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Guardian.MonthlyIncome"></label>
<input asp-for="Guardian.MonthlyIncome" class="form-control"/>
<span asp-validation-for="Guardian.MonthlyIncome" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="Guardian.EmployersName"></label>
<input asp-for="Guardian.EmployersName" class="form-control"/>
<span asp-validation-for="Guardian.EmployersName" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Guardian.WorkAddress"></label>
<input asp-for="Guardian.WorkAddress" class="form-control"/>
<span asp-validation-for="Guardian.WorkAddress" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="Guardian.MobileNo"></label>
<input asp-for="Guardian.MobileNo" class="form-control"/>
<span asp-validation-for="Guardian.MobileNo" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Guardian.PhysicalLocation"></label>
<input asp-for="Guardian.PhysicalLocation" class="form-control"/>
<span asp-validation-for="Guardian.PhysicalLocation" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="Guardian.Comments"></label>
<input asp-for="Guardian.Comments" class="form-control"/>
<span asp-validation-for="Guardian.Comments" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Education.EducationLevel"></label>
<input asp-for="Education.EducationLevel" class="form-control"/>
<span asp-validation-for="Education.EducationLevel" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="Education.School"></label>
<input asp-for="Education.School" class="form-control"/>
<span asp-validation-for="Education.School" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Education.AddressOfSchool"></label>
<input asp-for="Education.AddressOfSchool" class="form-control"/>
<span asp-validation-for="Education.AddressOfSchool" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="Education.HeadTeacher"></label>
<input asp-for="Education.HeadTeacher" class="form-control"/>
<span asp-validation-for="Education.HeadTeacher" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Education.Telephone"></label>
<input asp-for="Education.Telephone" class="form-control"/>
<span asp-validation-for="Education.Telephone" class="text-danger"></span>
</div>
</div>
<div class="form-row">
<div class="col">
<label asp-for="Siblings.NumberOfBrothers"></label>
<input asp-for="Siblings.NumberOfBrothers" class="form-control"/>
<span asp-validation-for="Siblings.NumberOfBrothers" class="text-danger"></span>
</div>
<div class="col">
<label asp-for="Siblings.NumberOfSisters"></label>
<input asp-for="Siblings.NumberOfSisters" class="form-control"/>
<span asp-validation-for="Siblings.NumberOfSisters" class="text-danger"></span>
</div>
</div>
<div class="form-group">
<input asp-for="FirstName" type="submit" value="Save Student" class="btn btn-primary"/>
</div>
</form>
答案 0 :(得分：0)
这是更新所有表格的方式
public void Edit(Student student)
{
var existingStudent = _context.Students.FirstOrDefault(s => s.Id == student.Id);
if (existingStudent != null)
{
//do the update to the database
_context.Entry(existingStudent).CurrentValues.SetValues(student);
_context.Entry(existingStudent).State = System.Data.Entity.EntityState.Modified;
//then update the parent this way
//first get the particular parent for this student
var parent = _context.Parents.FirstOrDefault(m => m.StudentId == existingStudent.Id);
_context.Entry(parent).CurrentValues.SetValues(student.Parents);
_context.Entry(parent).State = System.Data.Entity.EntityState.Modified;
//do the same for Educations
}
_context.SaveChanges();
}