mysql 数字加减

-- 创建一个示例表
CREATE TABLE example (
    id INT AUTO_INCREMENT PRIMARY KEY,
    value INT
);

-- 插入一些数据
INSERT INTO example (value) VALUES (10), (20), (30);

-- 进行加法运算
SELECT id, value + 5 AS new_value FROM example;

-- 进行减法运算
SELECT id, value - 5 AS new_value FROM example;

-- 使用 DECIMAL 类型进行高精度计算
CREATE TABLE example_decimal (
    id INT AUTO_INCREMENT PRIMARY KEY,
    value DECIMAL(10, 2)
);

INSERT INTO example_decimal (value) VALUES (10.50), (20.75), (30.25);

SELECT id, value + 5.50 AS new_value FROM example_decimal;

-- 创建索引
CREATE INDEX idx_value ON example(value);

-- 分批处理
SELECT id, value + 5 AS new_value FROM example WHERE id BETWEEN 1 AND 100;
SELECT id, value + 5 AS new_value FROM example WHERE id BETWEEN 101 AND 200;