如何制定這個SQL查詢？

Question

我希望start dates的所有員工的employee numbers和start dates等於最早的日期。

我知道這是錯誤的。但只是寫作來展示我想要的東西。

SELECT  start_date, employee_no 
FROM   [employees] 
WHERE  (start_date = MIN(start_date)) 

Answer 1

您近距離了！

SELECT  start_date, employee_no 
FROM   [employees] 
WHERE  start_date = (SELECT MIN(start_date) FROM employees) 

Answer 2

這將做到這一點：

SELECT  start_date, employee_no 
FROM   [employees] 
WHERE  start_date = (select MIN(start_date) from [employees]) 

Answer 3

SELECT start_date, employee_no 
FROM  [employees] 
WHERE  start_date = (SELECT MIN(start_date) FROM [employees]) 

Answer 4

我會使用一個公用表表達式（CTE）來做到這一點。這就像創建臨時表。

;with EmpInfo as 
(
    SELECT start_date, employee_no, MIN(start_date) OVER() as MinStartDate 
    FROM [employees] 
) 
SELECT start_date, employee_no FROM EmpInfo WHERE start_date = MinStartDate 

這裏有一個微軟網頁約Using Common Table Expressions