Linq查询表达式

选 项	语法
Project	select <expression>
Filter	where <expression>, distinct
Test	any(<expression>), all(<expression>)
Join	<expression> join <expression> on <expression> equals <expression>
Group	group by <expression>, into <expression>, <expression> group join<decision> on <expression> equals <expression> into <expression>
Aggregate	count([<expression>]), sum(<expression>), min(<expression>), max(<expression>), avg(<expression>)
Patition	skip [while] <expression>, take [while] <expression>
Set	union, intersect, except
Order	order by <expression>, <expression> [ascending | descending]