銆怢eetCode鍒烽銆慡QL-Second Highest Salary 鍙婃墿灞曚互鍙奜racle涓殑鐢ㄦ硶

Posted 2021-01-15

鏍囩锛?a href='http://www.mamicode.com/so/1/%e9%9a%be%e7%82%b9' title='闅剧偣'>闅剧偣   鍙栨暟   des   鍒嗛〉   xxxxx   蹇呴』   strong   寰幆璇彞   row   

Write a SQL query to get the second highest salary from the Employee table.

 

+----+--------+
| Id | Salary |
+----+--------+
| 1  | 100    |
| 2  | 200    |
| 3  | 300    |
+----+--------+

 

For example, given the above Employee table, the query should return 200 as the second highest salary. If there is no second highest salary, then the query should return null

+---------------------+
| SecondHighestSalary |
+---------------------+
| 200                 |
+---------------------+

 

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缈昏瘧锛?/span>

棰樼洰鐨勬剰鎬濇槸锛屽湪Employee琛ㄤ腑鎵惧埌绗簩澶х殑Salary瀛楁锛岀劧鍚庝互鍒悕鈥淪econdHighestSalary 鈥濈殑褰㈠紡杈撳嚭

 

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SQL锛?/p>

SELECT Max(Salary) as SecondHighestSalary FROM Employee WHERE Salary< ( SELECT  Max(Salary) FROM Employee);

 

 Max()鍑芥暟琛ㄧず杩斿洖鏈€澶у€硷紝濡傛灉娌℃湁鍒欒繑鍥濶ULL銆?/p>

Salary<( SELECT Max(Salary) FROM Employee) 鍒欐槸瀛愭煡璇㈢殑姒傚康銆?/p>

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Select * From Table_A Where key in (Select a,b From Table_B  Where Inr=鈥榅XXXXXX鈥?;

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銆€

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銆€銆€銆€銆€銆€銆€銆€銆€銆€銆€3銆佹暣涓〃閮芥槸鍚屼竴涓暟鎹殑鏋佺鎯呭喌銆?/p>

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SQL锛?/p>

SELECT IFNULL( (SELECT distinct Salary  FROM Employee order by Salary desc limit 1,1),null)as SecondHighestSalary;

鍏朵腑LIMIT 鐨勭敤娉曟槸杩欐牱鐨勶細

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SQL锛?/p>

SELECT DISTINCT(e2.Salary) FROM Employee e1,Employee e2 WHERE e2.Salary>=e1.Salary;

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锛?span style="color: #888888">sql绌哄€艰〃绀猴細

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LIMIT鏂规硶锛?/p>

SELECT IFNULL((SELECT DISTINCT(e2.Salary) FROM Employee e1,Employee e2 WHERE e2.Salary>e1.Salary LIMIT 1,1),NULL) as SecondHighestSalary;

鍗筹紝灏嗭細order by Salary desc 鏇挎崲涓?nbsp;WHERE e2.Salary>e1.Salary 

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COUNT鏂规硶

SELECT銆€e1.Salary FROM Employee e1 WHERE 2=(Select Count(distinct(e2.Salary)) from Employee e2 where e2.Salary >= e1.Salary)  as SecondHighestSalary;

涓婇潰涓ょ鏂规硶涔熷彲浠ョ敤浜庯紝鍙栦换鎰忕N浣嶆暟鎹椂銆?/p>

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 濡傛灉瑕佷娇鐢∣rder by 鏂规硶锛岄渶瑕佸啀鍔犱竴灞傚瓙鏌ヨ銆?/p>

COUNT-Order By 鏂规硶

SELECT銆€Salary FROM Employee  WHERE 2=(Select Count(distinct(Salary)) from (Select Salary From Employee order by Salary desc))  as SecondHighestSalary;

.

鐢变簬Oracle涓笉鑳戒娇鐢↙IMIT锛屾墍浠ユ垜浠敤rownum鏉ュ鐞嗘闂

Select Salary from (select amt ,rownum n From (Select distinct amt from Employee order by Salary desc)) where n=2;

鍏朵腑鐨刵=2鍙互鏇挎崲涓轰换鎰忔鏁存暟锛屽嵆涓虹N浣嶃€?/p>

鎬荤粨锛氬涓€涓瑕侀€氳繃涓嶅悓瑙掑害鎬濊€冨苟浼樺寲瑙ｇ瓟

杞浇浜庯細https://www.cnblogs.com/contixue/p/7057025.html