SQL与左外连接连接

Question

我试图从表中的一个表中获取一个额外的列，其中一个表位于左外连接中，

PFB我的表，

Create table tblEmployee(
ID int identity primary key,
FirstName nvarchar(50),
LastName nvarchar(50),
Gender nvarchar(50),
Salary int
)

Create table tblCourses(
CourseId int identity primary key,
CourseName nvarchar(50) not null
)


Create table tblEmpCourses(
EmpCourseSlNo int identity primary key,
EmpID int foreign key references tblEmployee(ID),
CourseID int foreign key references tblCourses(CourseId)
)

PFB插入语句，

insert into tblEmployee values ('FName1', 'LName1', 'Male', '10000')
insert into tblEmployee values ('FName2', 'LName2', 'Male', '15000')
insert into tblEmployee values ('FName3', 'LName3', 'Female', '30000')
insert into tblEmployee values ('FName4', 'LName4', 'Male', '50000')
insert into tblEmployee values ('FName5', 'LName5', 'Male', '60000')
insert into tblEmployee values ('FName6', 'LName6', 'Female', '0000')
insert into tblEmployee values ('FName7', 'LName7', 'Male', '10000')
insert into tblEmployee values ('FName8', 'LName8', 'Male', '30000')

insert into tblCourses values ('Asp.net')
insert into tblCourses values ('C#')
insert into tblCourses values ('WebAPI')
insert into tblCourses values ('SQL')
insert into tblCourses values ('WCF')
insert into tblCourses values ('JS')
insert into tblCourses values ('CSS')
insert into tblCourses values ('JAVA')

insert into tblEmpCourses values (1, 1)
insert into tblEmpCourses values (1, 2)
insert into tblEmpCourses values (1, 3)
insert into tblEmpCourses values (1, 4)

如何编写查询以使用所有员工firstName获取数据，其中他已经订阅了任何课程，或者没有订阅courseID和courseName

尝试使用以下查询，但无法在select语句中添加CourseName，如何在此添加一个连接b / w tblEmpCourses表和使用left_outer_join的tblCourses以获取CourseName

所以我希望数据为

FirstName CourseID CourseName

  select FirstName, CourseID 
  from   tblEmployee 
  left outer join tblEmpCourses 
  on     tblEmployee.ID = tblEmpCourses.EmpID;

根据以下快照预期结果

Answer 1

SELECT
 e.FirstName,
 c.CourseID,
 c.CourseName
FROM tblEmployee e
LEFT JOIN tblEmpCourses ec ON e.ID =ec.EmpID
LEFT JOIN tblCourses  c ON c.CourseID = ec.CourseID

类似的东西？

Answer 2

select FirstName, CourseID, CourseName
from   tblEmployee 
left outer join tblEmpCourses 
on     tblEmployee.ID = tblEmpCourses.EmpID
left outer join tblCourses
on tblEmpCourses.CourseId = tblCourses.CourseId

Answer 3

--Inner join for matching records
 SELECT FirstName, C.CourseID ,tC.CourseName
  FROM   tblEmployee E
  INNER JOIN 
    tblEmpCourses C 
      ON     E.ID = C.EmpID
  INNER join tblCourses tc
    ON tc.CourseId=C.CourseID   

输出

FirstName   CourseID    CourseName
FName1      1          Asp.net
FName1      2          C#
FName1      3          WebAPI
FName1      4          SQL