Question

我有3张表，雇员，部门和薪水

这是部门模型：

public partial class Department
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public Department()
    {
        this.Employees = new HashSet<Employee>();
    }

    public int Id { get; set; }
    public string Name { get; set; }
    public Nullable<int> Parent_Id { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<Employee> Employees { get; set; }
}

这是员工模型：

public partial class Employee
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public Employee()
    {
        this.Salaries = new HashSet<Salary>();
    }

    public int Id { get; set; }
    public string Name { get; set; }
    public Nullable<int> Department_id { get; set; }

    public virtual Department Department { get; set; }
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<Salary> Salaries { get; set; }
}

这是薪资模式：

 public partial class Salary
{
    public int Id { get; set; }
    public Nullable<System.DateTime> Date { get; set; }
    public Nullable<decimal> Amount { get; set; }
    public Nullable<int> Employee_Id { get; set; }

    public virtual Employee Employee { get; set; }
}

我需要获得每个部门的平均工资

所以我为它创建了ViewModel

 public class SalariesViewModel
{
    public string DepartmentName { get; set; }
    public decimal AverageSalary { get; set; }
}

尝试编写此方法

**public List<SalariesViewModel> GetAverageSalary() {

        var massagedEmployees = db.Employees.GroupBy(e => e.Department)
                              .Select(g =>
                                new {
                                    Department = g.Key,
                                    SalaryAvg = g.Average(x => x.Salaries)
                                });
    }**

但我无法设置x.Salaries.Amount。

我如何计算每个部门的平均工资？

更新

以下是Department，Employees和Salary的示例输入

薪资投入

雇员输入

部门输入

所以在输出时我需要像这样的部门 - 200 $

Answer 1

由于您需要员工当前工资的平均值，请将其分为2个查询

首先生成一个包含员工当前工资的对象

var employees = db.Employees.Select(x => new
{
    Department = x.Department.Name,
    Name = x.Name,
    Salary = x.Salaries.OrderByDescending(y => y.Date).First().Amount
});

请注意，这假定员工至少包含一个薪水

接下来按Department

对这些对象进行分组

var data = employees.GroupBy(m => m.Department).Select(x => new SalariesViewModel
{
    DepartmentName = x.Key,
    AverageSalary = x.Average(y => y.Salary)
}).ToList();
return data;

Answer 2

正如许多人在评论中所解释的那样，您可能正在寻找基于最近一个月的平均工资。在这种情况下，你可以通过

得到这个

Employees.GroupBy(e => e.Department.Name)
                          .Select(g =>
                            new {
                                Department = g.Key,
                                SalaryAvg = g.Average(x => x.Salaries.OrderByDescending(s => s.Date).FirstOrDefault().Amount)
                            });

如果你坚持要获得针对员工的所有可用价值（我怀疑），你可以这样做

Employees.GroupBy(e => e.Department.Name)
                          .Select(g =>
                            new {
                                Department = g.Key,
                                SalaryAvg = g.Average(x => x.Salaries.Average(s => s.Amount))
                            });

注意：上述查询中没有处理空值。

获得部门的平均工资（ASP.NET）

2 个答案: