列组合参数

Question

为什么我的错误？或者是否可以进行这样的查询？

select Employee.EmployeeID, Employee.LastName + ', ' + Employee.FirstName + ' ' + Employee.MiddleName as EmployeeFullName
From Employee
Where EmployeeFullName = 'someFullName' 

列名称无效＆＃39; EmployeeFullName＆＃39;。

Answer 1

可能是因为任何field（lastname, firstname,middlename）可能是null而发生错误 试试这个

select 
Employee.EmployeeID, 
isnull(Employee.LastName,'') + ', ' + isnull(Employee.FirstName,'') + ' ' + isnull(Employee.MiddleName,'') as EmployeeFullName
From Employee
Where AuthorFullName = 'someFullName'

编辑1）

你的条件错误，这就是你得到的原因（无效的列名'AuthorFullName'。）这个错误。

编辑2）

select 
    Employee.EmployeeID, 
    isnull(Employee.LastName,'') + ', ' + isnull(Employee.FirstName,'') + ' ' + isnull(Employee.MiddleName,'') as EmployeeFullName
    From Employee
    Where isnull(Employee.LastName,'') + ', ' + isnull(Employee.FirstName,'') + ' ' + isnull(Employee.MiddleName,'') = 'someFullName'

Answer 2

SELECT FullName FROM 
( 
    SELECT 
        FullName = LastName + ', ' + FirstName + ' ' + MiddleName
        FROM Employee  
) sub 
WHERE sub.FullName = 'someFullName'