Q1:加入子查詢
SELECT SUBSTR(o.first_name,1,1)||' '||o.last_name "NAME",
FROM employees o
WHERE o.salary >
(SELECT AVG(i.salary)
FROM employees i
WHERE i.department_id =
o.department_id)
我有部門標識和部門名稱部門表||如何將其加入到此結果中以顯示子查詢和dep名稱的結果?
q2)在添加最後一行後會拋出一個錯誤:爲什麼?
SELECT SUBSTR(first_name, 1, 1) || ' ' || last_name "Employee Name", department_id "Department Id", to_char(NULL) "Department Name", to_char(NULL) " City"
FROM employees
UNION
SELECT to_char(NULL) "Employee Name" , department_id "Department ID", department_name "Department Name", to_char(NULL)" City"
FROM departments
UNION
SELECT to_char(NULL) "Employee Name" , to_char(NULL) "Department Id", to_char(NULL) "Department Name" ,to_char(NULL)"City"
FROM locations
有關錯誤,請添加你所得到的錯誤。至於你的查詢,如果你添加你的表結構和一些示例數據,也許我們可以幫助你以更好的方式實現這一點。至於 –
@Filipe:錯誤:ORA-01790:表達式必須與相應的表達式具有相同的數據類型..我想加入到q2中的表具有department_id,department_name .. – user3026370
第一個我不知道如何處理獲得三列:名稱和工資(來自子查詢)以及來自其他表的名稱 – user3026370