1.SELECT语句

(1) 普通查询

var list = from s in db.student select s.stuname;

(2) 匿名类查询

var list = from c in db.customer select new {name = c.firstname+" "+c.lastname};

(3) 条件查询

var list = from l in db.grade select new {name = l.name; level = l.score>60 "pass":"failed"};

(4) 指定类型查询

var list = from e in db.card select new Name {first = e.firstname;last=e.lastname};

(5) 筛选查询

var list = from s in db.student where s.id < 10 select s.name;

(6) 匿名对象嵌套查询

var list = from e in db.data select new {

company = new { companyname = e.name;

companyphone = e.phone},

manager = e.manager;

}

(7) 调用方法查询

var list = from s in db.student select new {name=s.name,age=ageconvert(s.age)};

(8) Distinct形式

var list = (from s in db.student select s.name).distinct();

2. WHERE语句

(1) 普通条件查询

var list = from s in db.student where s.name = "Jack" select s;

(2) 关系条件查询

var list = from s in db.student where s.age>20 && s.sex ==1;

var list = db.student.where(s=>s.age>20).where(s=>s.sex==1)

(3) First形式（相当于SQL中Top(1)）

student stu = db.student.first(s=>s.age>20);

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