刪除SQL Server上只有一條記錄

Question

假設有一個表EMPLOYEE與SQL Server上的列ID (int), Name (nvarchar), Surname(nvarchar)。

這就是你所知道的全部。您無法看到表格中的數據。

您被命令只刪除其中一個名爲'Alice'的記錄。

你會如何編寫適當的查詢？

Answer 1

DELETE TOP (1) 
FROM EMPLOYEE 
WHERE Name='Alice' 

Answer 2

DELETE TOP (1) FROM EMPLOYEE WHERE Name = 'Alice' 

Answer 3

在SQL Server：

DELETE TOP 1 FROM EMPLOYEE WHERE Name = 'Alice' 

Answer 4

所有建議的答案在這裏主要是相似的，所有的人是最佳至於你介紹你的問題。

但這會強制您的代碼刪除Name ='Alice'的第一條記錄。但是，如果您需要有一點額外的權力來選擇刪除表中有多個「Alice」的情況。但當然的ID必須是一個Primary Key或Unique

SELECT FROM EMPLOYEE ID, Surname WHERE Name = 'Alice' 

這將顯示的結果的話，你可以把目標記錄的ID將被刪除，並將其放置在下面的查詢（讓我們說的要刪除的記錄的ID是56）

DELETE FROM EMPLOYEE WHERE ID = 56 

Answer 5

declare @Holder table (EmployeeKey int , Name varchar(24) , Surname varchar(24)) 


Insert into @Holder (EmployeeKey , Name , Surname) 
      select 201 , 'Alice' , 'Smith' 
union all select 102 , 'Mary' , 'Smith' 
union all select 203 , 'Alice' , 'Henderson' 
union all select 104 , 'John' , 'Smith' 
union all select 105 , 'Paul' , 'Johnson' 
union all select 206 , 'Alice' , 'Jones' 

Delete @Holder 
/* Select * ............. while debugging, you can remove the 'Delete @Holder' and put in a 'Select *' to see the results (of what ~will be deleted) */ 
From 
@Holder h 
join 
(select top 1 EmployeeKey from @Holder innerH where Name = 'Alice' /* order by EmployeeKey DESC */) as derived1 
on h.EmployeeKey = derived1.EmployeeKey 

select * from @Holder order by Name , EmployeeKey 

/* 
order by EmployeeKey DESC is optional, aka, if you want to "prefer" which one gets popped for delete, you can tweak it as needed 
*/