use scratch
--drop table customers
--drop table employees
create table customers (customerid int, name varchar(10))
create table employees (employeeid int, name varchar(10))
insert customers (customerid, name)
select 1,'Dave' union all
select 2,'John' union all
select 3,'Tom' union all
select 4,'Dick' union all
select 5,'Harry'
insert employees (employeeid, name)
select 2,'John' union all
select 4,'Dick' union all
select 6,'Anne' union all
select 8,'Martha'
GO
SELECT * 
 FROM dbo.Customers 
  MIDDLE JOIN dbo.Employees ON CustomerID = EmployeeID

SELECT * FROM dbo.Customers
  MIDDLE JOIN dbo.Employees ON CustomerID=EmployeeID

SELECT * FROM dbo.Customers AS MIDDLE
  JOIN dbo.Employees ON CustomerID=EmployeeID