如何使用 Entity Framework Core 在数据库中添加值

Question

模型类：

public class BulkAttendance
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }
    public int EmployeeCategoryId { get; set; }
    public int EmployeeLabourGroup {  get; set; }
    public int CompanyId { get; set; }
    public int BranchId { get; set; }
    public int FinancialYearId { get; set;}
    public int ApprovalStatus { get; set; }
    public int ApprovalLevel { get; set; }
    public DateTime? ApprovedDate { get; set; }
    public DateTime FromDate { get; set; }
    public DateTime ToDate { get; set; }
    public int UserId { get; set; }
    public int CurrencyPrecision { get; set; }
    public List<BulkAttendaceDetail> AttendanceDetail { get; set; }

}

public class BulkAttendaceDetail 
{
    public string AttendanceId { get; set; }
    public string FullName { get; set; }
    public DateTime DateWorked { get; set; }
    public DateTime LoginTime { get; set; }
    public DateTime LogoutTime { get; set; }
    public int Employeeid { get; set; }
    public int ProjectId { get; set; }
    public string ProjectName {  get; set; }
    public int Category { get; set; }
    public int WorkId { get; set; }
    public decimal Amount { get; set; }
    public int Work { get; set; }
    public decimal OverTime { get; set; }
    public decimal OverTimeAmount { get; set; }
    public string WorkCategoryName { get; set; }
    public string WorkShortName { get; set; }
    public decimal OvertimeRate { get; set; }
    public DateTime TimeIn { get; set; }
    public DateTime TimeOut { get; set; }
    public decimal SalaryAmount { get; set; }
}

我正在尝试在我的项目中发布

employeeAttendance

。问题是

BulkAttendance

模型 ID 是数据库生成的。我想将

Id

值分配给

AttendanceId

详细模型中的

BulkAttendance

- 我该如何处理这种情况？

这就是我尝试将员工的

Attendance

插入数据库的方式

public async Task BulkAttendanceEntry(List<BulkAttendance> attendances)
{
    try
    {
        foreach (var attendance in attendances)
        {
            await _bulkAttendanceContext.tbl_AttendanceMaster.AddAsync(attendance);

            if (attendance.AttendanceDetail != null && attendance.AttendanceDetail.Any())
            {
                foreach(var attendanceDetail in attendance.AttendanceDetail)
                {
                    
                }
            }
        }
    }
    catch(Exception)
    {
         throw;
    }
}

Answer 1

在 Entity Framework Core 中，如果您想在像您这样的两个实体之间定义“一对多”关系，则必须在子实体 BulkAttendanceDetail 中添加对父实体 BulkAttendance 的引用。因此，将在子表中创建一个外键，指向父表。当您将新实体正确添加到 BulkAttendanceDetail 表时，新行将具有一个引用属性（外键），其中包含父 BulkAttendance 表中其父行的相应 ID。 要实现此机制，您必须修改 BulkAttendanceDetail 类：

public class BulkAttendanceDetail
{
    [Key]
    public int Id { get; set; }  //primary key of BulkAttendanceDetail table                                    
    public int BulkAttendanceId { get; set; } //foreign key to BulkAttendance table                                   
    BulkAttendance BulkAttendance { get; set; } //parent class
    public string FullName { get; set; }
    public DateTime DateWorked { get; set; }
    public DateTime LoginTime { get; set; }
    public DateTime LogoutTime { get; set; }
    public int Employeeid { get; set; }
    public int ProjectId { get; set; }
    public string ProjectName { get; set; }
    public int Category { get; set; }
    public int WorkId { get; set; }
    public decimal Amount { get; set; }
    public int Work { get; set; }
    public decimal OverTime { get; set; }
    public decimal OverTimeAmount { get; set; }
    public string WorkCategoryName { get; set; }
    public string WorkShortName { get; set; }
    public decimal OvertimeRate { get; set; }
    public DateTime TimeIn { get; set; }
    public DateTime TimeOut { get; set; }
    public decimal SalaryAmount { get; set; }
}

BulkAttendanceId

属性将是您的外键。当您向上下文添加一个包含已填充子列表的新 BulkAttendance 对象（父对象）时：

List<BulkAttendanceDetail> AttendanceDetail

外键将在保存新父对象时自动生成：

await _bulkAttendanceContext.SaveChangesAsync();