--一本錯誤的記錄 insert into Book values('錯誤時怎樣練成的',111) --左連接 select s.name,b.name from student as s left join Book as b on s.id=b.studentid --右連接 select s. ...
--一本錯誤的記錄 insert into Book values('錯誤時怎樣練成的',111) --左連接 select s.name,b.name from student as s left join Book as b on s.id=b.studentid --右連接 select s.name,b.name from student as s right join Book as b on s.id=b.studentid 要用Linq實現左連接，寫法如下 DataClasses1DataContext db = new DataClasses1DataContext(); var leftJoinSql = from student in db.Student join book in db.Book on student.ID equals book.StudentID into temp from tt in temp.DefaultIfEmpty() select new { sname= student.Name, bname = tt==null?"":tt.Name//這裡主要第二個集合有可能為空。需要判斷 }; 用Linq實現右連接，寫法如下 DataClasses1DataContext db=new DataClasses1DataContext(); var rightJoinSql = from book in db.Book join stu in db.Student on book.StudentID equals stu.ID into joinTemp from tmp in joinTemp.DefaultIfEmpty() select new { sname=tmp==null?"":tmp.Name, bname=book.Name };
