C# 初步学习LINQ

匿名类型

new {FieldProp=InitExpr,FieldProp=InitExpr,...}

var student=new{Name="Mary Jones",Age=19,Major="History"};

查询表达式由查询体后的from子句组成。有关查询表达式需要了解一些重要事项：

from s in studentsjoin c in studentsInCourses on s.StID equals c.STIDwhere c.CourseName=="History"select.LastName;

var someInts=from a in groupA                from b in groupB                where a>4&&b<=8                select new{a,b,sum=a+b};//匿名类型对象

var someInts=from a in groupA                     from b in groupB                     let sum=a+b                              where sum>=11            ←条件1                     where a==4               ←条件2                     select new{a,b,sum};

var someInts=from a in groupA                     from b in groupB                     let sum=a+b                              where sum>=11            ←条件1                     where a==4               ←条件2                     select new{a,b,sum};

var query=from s in students                  group s by s.Major;

var someInts=from a in groupA                     join b in groupB on a equals b                     into groupAandB                     from c in groupAandB                     select c;