使用选择加入两个表，只显示几列，也有一个标准

Question

我搜索了这个地方，但没有找到答案，我可以找到，因为别人有什么不同。

USE TestDatabase 
Select Firstname,Lastname,Salary From Employee as E 
Join JobTitle as J 
on E.JobTitleID = J.JobTitleID 

WHERE Salary 
BETWEEN $25000.00 AND $50000.00 

这工作，但我试图显示来自JOBTITLE表两列，我也不知道搜索或谷歌，不能没有找到一个简单的答案是什么字。任何人都可以帮助一定要简单一些，但我很困惑。我使用Server 2008的T-SQL学校

Answer 1

您可以使用表JobTitle这是J的别名来选择要选择

Select Firstname, Lastname, Salary, 
    j.Field1, j.Field2 ... -- and other fields you want to select here 
From Employee as E 
Join JobTitle as J 
on E.JobTitleID = J.JobTitleID 

WHERE Salary 
BETWEEN $25000.00 AND $50000.00 

Answer 2

Select E.Firstname, E.Lastname, E.Salary, J.Column1, J.Column2 
    From Employee as E 
     Join JobTitle as J 
      on E.JobTitleID = J.JobTitleID 
    WHERE E.Salary BETWEEN $25000.00 AND $50000.00 

Answer 3

你是说像这样的任何额外列？

USE TestDatabase 
Select Firstname,Lastname,Salary,J.YourcolumnfromJobTitle From Employee as E 
Join JobTitle as J 
on E.JobTitleID = J.JobTitleID 

WHERE Salary 
BETWEEN $25000.00 AND $50000.00 

Answer 4

你应该针对表像这样用别名：

USE TestDatabase 
Select E.Firstname,E.Lastname,E.Salary,J.Column1,j.Column2 From Employee as E 
Join JobTitle as J 
on E.JobTitleID = J.JobTitleID 

WHERE E.Salary 
BETWEEN $25000.00 AND $50000.00 

Answer 5

使用别名来设置谁是你使用的字段的表。

Select 
    E.Firstname,E.Lastname,E.Salary, 
    j.JobTitle, j.Otherfieldyouwanttoselect 
From Employee as E Join JobTitle as J on E.JobTitleID = J.JobTitleID 
WHERE 
    Salary BETWEEN $25000.00 AND $50000.00