[英]Checking if mysql query provides the best solution to the question
列出在代碼為 1 且每小時工資為 40 歐元的 EmployeeType 中工作的所有員工的姓名和地址。
我想知道這是否是從上述問題中檢索信息的最佳方式
SELECT e.EmployeeName , e.EmployeeAddress
FROM Employee e JOIN EmployeeType et ON e.EmployeeType = et.EmployeeType
HAVING e.EmployeeCode = (1) AND et.TotalPay = (40);
我不會在此查詢中使用“HAVING”,我更喜歡 WHERE 條件或在加入時添加更多參數。 您可以在此LINK上閱讀有關 HAVING 的信息,Having 與 WHERE 條件略有不同,因為它在查詢結果后應用。
第一個具有簡單 WHERE 條件的解決方案
SELECT e.EmployeeName , e.EmployeeAddress
FROM Employee e
INNER JOIN EmployeeType et ON e.EmployeeType = et.EmployeeType
WHERE e.EmployeeCode = '1' AND et.TotalPay = '40';
第二種解決方案在加入時添加更多參數
SELECT e.EmployeeName , e.EmployeeAddress
FROM Employee e
INNER JOIN EmployeeType et ON (e.EmployeeType = et.EmployeeType AND et.TotalPay = '40')
WHERE e.EmployeeCode = '1' ;
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