c＃Linq方法使用GroupBy和Select(c# Linq Method with GroupBy and Select)

c＃Linq方法使用GroupBy和Select(c# Linq Method with GroupBy and Select)

我有以下型号：

public class HeadCount { public int Id { get; set; } public int ContractId { get; set; } public string FiscalYear { get; set; } public string TaskOrder { get; set; } public decimal ContractHours { get; set; } public int PersonId { get; set; } public string CompanyName { get; set; } public string UserId { get; set; } public int ClinAssignId { get; set; } }

使用标准的sql，我在SSMS中运行以下脚本：

select personid, sum(contracthours) as hours from headcounts where personid != 0 group by personid

我正在努力将其转换为LINQ menthod调用。 这是我试过的：

var results = _context.HeadCounts .GroupBy(p => p.PersonId) .Select(n => new {personid = n.Key, hours = n.Sum(ContractHours)});

它不喜欢Sum中的ContractHours 。 我甚至尝试过n.ContractHours

我究竟做错了什么？

I have the following model:

public class HeadCount { public int Id { get; set; } public int ContractId { get; set; } public string FiscalYear { get; set; } public string TaskOrder { get; set; } public decimal ContractHours { get; set; } public int PersonId { get; set; } public string CompanyName { get; set; } public string UserId { get; set; } public int ClinAssignId { get; set; } }

Using standard sql, I have the following script I run in SSMS:

select personid, sum(contracthours) as hours from headcounts where personid != 0 group by personid

I am stubbling trying to convert this to a LINQ menthod call. This is what I tried:

var results = _context.HeadCounts .GroupBy(p => p.PersonId) .Select(n => new {personid = n.Key, hours = n.Sum(ContractHours)});

It does not like the ContractHours in the Sum. I have even tried n.ContractHours

What am I doing wrong?

最满意答案

如果集合不是原始数字集合，则Sum采用选择器，因此您需要：

n.Sum(p => p.ContractHours)

Thanks to Robs comment in the original question, this was the answer I was looking for.