C# 编程/关键字/select

上下文关键字select用于确定在查询结束时返回哪些变量，例如“from item in dataset select id”。紧接在上下文关键字select之后是一个表达式，它可能像每个返回项目的单个属性或项目本身一样简单。表达式可以包含属性列表，也可以是更复杂的表达式，将查询的返回结果转换为新的类型。

C# 关键字
abstract as base bool break byte case catch char checked class const continue decimal default delegate do double else enum event explicit extern false finally fixed float for foreach goto if implicit in int interface internal is lock long namespace new null object operator out override params private protected public readonly ref return sbyte sealed short sizeof stackalloc static string struct switch this throw true try typeof uint ulong unchecked unsafe ushort using var virtual void volatile while
C# 特殊标识符（上下文关键字）
add alias async await dynamic get global nameof partial remove set value when where yield
上下文关键字（用于查询）
ascending by descending equals from group in into join let on orderby select where