Oracle SQL CASE給出錯誤

Question

我試圖給我的查詢添加一個額外的列。根據平均工資水平，它應該寫入BELOW或ABOVE到列中，但不起作用。問題是什麼？

SELECT CONCAT(firstname, lastname) AS name 
FROM workers 
CASE 
    WHEN salary < avg(salary) THEN 'BELOW' 
    WHEN salary > avg(salary) THEN 'ABOVE' 
    ELSE 'AVARAGE' 
END; 

Answer 1

的case所屬的select子句中：

SELECT CONCAT(firstname, lastname) AS name 
     (CASE WHEN salary < avg(salary) THEN 'BELOW' 
      WHEN salary > avg(salary) THEN 'ABOVE' 
      ELSE 'AVERAGE' 
     END) 
FROM workers; 

這正好解決了第一個問題。接下來的問題是你有一個聚合功能，但沒有聚合。你真正想要的是一個分析功能：

SELECT CONCAT(firstname, lastname) AS name 
     (CASE WHEN salary < AVG(salary) OVER() THEN 'BELOW' 
      WHEN salary > AVG(salary) OVER() THEN 'ABOVE' 
      ELSE 'AVERAGE' 
     END) 
FROM workers;