SELECT `contract_fine` AS TotalFine FROM `contract`
NATURAL JOIN `rented_vehicle` WHERE `contractID` = 3;
这会返回数字行,我该如何将它们加在一起,我似乎做不到。
最佳答案
SELECT SUM(`contract_fine`) AS TotalFine FROM `contract`
NATURAL JOIN `rented_vehicle` WHERE `contractID` = 3;
就这么简单。
关于mysql - 如何对 mysql 行求和,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/14225811/