SQLite SUM() 函数 - SQLite 基础教程 - 简单教程，简单编程

SQLite SUM() 函数用于计算一个数值列的总和

SELECT sum(fieldname) FROM tablename;

先运行下面的 SQLite SQL 语句创建测试数据

DROP TABLE tbl_employee;

CREATE TABLE tbl_employee (
   id INTEGER PRIMARY KEY AUTOINCREMENT  NOT NULL,
   name           CHAR(64) NOT NULL,
   age            INTEGER  NOT NULL,
   city           CHAR(64),
   salary         REAL
);



INSERT INTO tbl_employee (name,age,city,salary) VALUES
    ('张三', 25, 'pek', 102400.00 ),
    ('李四', 18, 'shanghai', 88888.00 ),
    ('王五', 22, 'hangzhou', 22000.00 ),
    ('孙六', 32, 'pek', 32000.00 ),
    ('钱七', 25, 'shanghai', 25000.00 ),
    ('赵二', 45, 'pek', 45800.00 ),
    ('冯九', 37, 'chengdu', 15000.00 );

然后运行下面的 SQLite 语句计算 tbl_employee 表 salary 的总和

SELECT sum(salary) FROM tbl_employee;

输出结果如下

sum(salary)
-----------
331088.0

可以把 fieldname 替换成任何表达式

SELECT sum(salary/age) FROM tbl_employee;

输出结果如下

sum(salary/age) 
----------------
13457.4054054054

如果要计算城市薪水的总和，那么就要使用 GROUP BY 语句了

SELECT city,sum(salary) FROM tbl_employee GROUP BY city;

输出结果如下

city        sum(salary)
----------  -----------
chengdu     15000.0    
hangzhou    22000.0    
pek         180200.0   
shanghai    113888.0