版權聲明
- 本文原創作者:清風不渡
- 博客地址:https://blog.csdn.net/WXKKang
首先創建一組測試數據用於學習SUM()函數,代碼如下:
CREATE TABLE student(
s_id varchar(50) NOT NULL PRIMARY KEY,
s_name varchar(50),
s_gender varchar(50),
s_age int
)
INSERT INTO student(s_id,s_name,s_gender,s_age) VALUES ('S101','Tom','male',18);
INSERT INTO student(s_id,s_name,s_gender,s_age) VALUES ('S102','Lucy','female',18);
INSERT INTO student(s_id,s_name,s_gender,s_age) VALUES ('S103','Jack','male',19);
INSERT INTO student(s_id,s_name,s_gender,s_age) VALUES ('S104','Bruce','male',16);
INSERT INTO student(s_id,s_name,s_gender,s_age) VALUES ('S105','Jayce','male',23);
一、SUM()函數
SUM()函數用於返回數字列的總和
1、基本語法
基本語法如下:
SELECT SUM(column_name)
FROM table_name
WHERE condition;
2、示例
下面我們就通過上面的實例查找出學生表中學生的年齡總和,代碼如下:
SELECT SUM(s_age) FROM student;
執行結果如下: