如何在LINQ中做GroupBy多列
SQL中类似的代码:
SELECT * FROM <TableName> GROUP BY <Column1>,<Column2>
如何将其转换为LINQ:
QuantityBreakdown
(
MaterialID int,
ProductID int,
Quantity float
)
INSERT INTO @QuantityBreakdown (MaterialID, ProductID, Quantity)
SELECT MaterialID, ProductID, SUM(Quantity)
FROM @Transactions
GROUP BY MaterialID, ProductID
当前回答
您还可以使用Tuple<>作为强类型分组。
from grouping in list.GroupBy(x => new Tuple<string,string,string>(x.Person.LastName,x.Person.FirstName,x.Person.MiddleName))
select new SummaryItem
{
LastName = grouping.Key.Item1,
FirstName = grouping.Key.Item2,
MiddleName = grouping.Key.Item3,
DayCount = grouping.Count(),
AmountBilled = grouping.Sum(x => x.Rate),
}
其他回答
程序样例:
.GroupBy(x => new { x.Column1, x.Column2 })
var Results= query.GroupBy(f => new { /* add members here */ });
group x by new {x. col, x. col}
.GroupBy(x => (x.MaterialID, x. producd))
使用匿名类型。
Eg
group x by new { x.Column1, x.Column2 }
