c# linq查询
List<DeptInfo> deptList = (from emp in empList
where emp.Status == "在职" //筛选“在职”员工
orderby emp.DeptID ascending //按“部门ID”排序
group emp by new //按“部门ID”和“部门名称”分组
{
emp.DeptID,
emp.DeptName
}
into g
select new DeptInfo()
{
DeptID = g.Key.DeptID,
DeptName = g.Key.DeptName,
EmplayeeCount = g.Count(), //统计部门员工数量
WageSum = g.Sum(a => a.Wage), //统计部门工资总额
WageAvg = g.Average(a => a.Wage), //统计部门平均工资
EmplayeeList = (from e in g //归集部门员工列表
select new Emplayee()
{
EmpID = e.EmpID,
EmpName = e.EmpName
}
).ToList()
}).ToList();
拼接分组后的字符：
1：
var result = from item in tbl
group item by item.name into g
let ids = g.Select(b => b.id.ToString()).ToArray()
select new { id = String.Join(",", ids), name = g.Key };:2：
var tbl2 = from item in db.tbl select new {id=item.id.ToString(),item.name };
var result = from item in tbl2
group item by item.name into g
select g.Aggregate(
(workingSentence, next) =>
new {
ids =workingSentence.id + "," +next.id , name = g.Key
}
);//分组 求和
var temp = (from a in student
from p in syncchip
// join p in syncchip
//on c.id equals p.user_id
where a.class_id == index
orderby a.id
group new {a.id,a.name,a.className,a.sex ,a.head_img, p.user_id }
by new { a.id, a.name, a.className, a.sex, a.head_img} into g
select new
{
stdent_id = g.Key.id,
name = g.Key.name,
className = g.Key.className,
sex = g.Key.sex,
head_img = g.Key.head_img,
cou= g.Count(c => c.user_id== g.Key.id)
}).ToList();
var temp = (from a in student
from p in syncchip
// join p in syncchip
//on c.id equals p.user_id
where a.class_id==index
orderby a.id
group a by new { a.id,a.name,a.className ,a.sex,a.head_img } into g
select new
{
stdent_id =g.Key.id,
name = g.Key.name,
className = g.Key.className,
sex = g.Key.sex,
head_img=g.Key.head_img,
cou = (from e in syncchip
where e.user_id == g.Key.id
group e by e.user_id into b
select new
{
cou = g.Count()
}
).Count()
}).ToList();
List<StudentClass> list = new List<StudentClass>();
foreach (var i in temp)
{
list.Add(new StudentClass {student_id =i.stdent_id,name=i.name,cou=i.cou ,className=i.className,sex=i.sex,head_img=i.head_img});
}
var temp = (from a in Waybills
from p in PlanOrders
where a.PlanId == p.Id
orderby a.SendTime
group a
by new { a.ProId ,a.ProName, a.GmId, a.GmName, a.GmModel, p.PlanNumber } into g
select new
{
Time= teme.ToString(),
Type="当日汇总",
ProId = g.Key.ProId,
Id= g.FirstOrDefault().Id,
PlanId = g.FirstOrDefault().PlanId,
ProName = g.Key.ProName,
GmId = g.Key.GmId,
GmName = g.Key.GmName,
GmModel = g.Key.GmModel,
//计划数量
PlanNumber=g.Key.PlanNumber,
//完成数量
Sum = g.Sum(a => a.LoadingWeight),
//完成率
CompletionRate = decimal.Round(((g.Sum(a => a.LoadingWeight) / g.Key.PlanNumber) * 100),2),
//派车数量
cou=g.Count(),
//完成车数
Complete = g.Count(a => a.Status==2)
//备注
}).ToList();