MySQL 常用业务 SQL

这篇更贴近"日常写业务"的 SQL，不讲理论，强调能直接拿去改。

一、按时间范围的常用查询

-- 最近 7 天订单
SELECT *
FROM orders
WHERE create_time >= NOW() - INTERVAL 7 DAY;

-- 指定日期
SELECT *
FROM orders
WHERE create_time >= '2026-04-01 00:00:00'
  AND create_time <  '2026-04-02 00:00:00';

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二、状态机更新（防止重复更新）

-- 只允许从 UNPAID -> PAID
UPDATE orders
SET status = 'PAID', pay_time = NOW()
WHERE id = ? AND status = 'UNPAID';

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三、库存扣减（防止超卖）

UPDATE stock
SET quantity = quantity - 1
WHERE sku_id = ? AND quantity > 0;

配套判断：受影响行数为 0 就表示库存不足。

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四、批量更新（避免一条条改）

UPDATE user
SET status = 'DISABLED'
WHERE last_login < NOW() - INTERVAL 180 DAY;

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五、存在即更新（UPSERT）

INSERT INTO user_profile (user_id, nickname, avatar)
VALUES (?, ?, ?)
ON DUPLICATE KEY UPDATE
nickname = VALUES(nickname),
avatar = VALUES(avatar);

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六、批量插入（提高吞吐）

INSERT INTO audit_log (user_id, action, create_time)
VALUES
  (101, 'LOGIN', NOW()),
  (102, 'LOGIN', NOW()),
  (103, 'LOGIN', NOW());

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七、分页查询（业务常规）

-- 传统分页（页数不大可用）
SELECT id, user_id, status, create_time
FROM orders
ORDER BY create_time DESC
LIMIT 0, 20;

-- 游标分页（更稳）
SELECT id, user_id, status, create_time
FROM orders
WHERE (create_time < ? OR (create_time = ? AND id < ?))
ORDER BY create_time DESC, id DESC
LIMIT 20;

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八、模糊搜索（建议加前缀）

-- 前缀匹配可用索引
SELECT * FROM user WHERE nickname LIKE '张%';

%张% 这种全模糊通常走不到索引。

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九、查重（业务常用）

SELECT email, COUNT(*) AS cnt
FROM user
GROUP BY email
HAVING cnt > 1;

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十、取某用户最新一条记录

SELECT *
FROM login_log
WHERE user_id = ?
ORDER BY create_time DESC
LIMIT 1;

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十一、报表类统计（按天聚合）

SELECT DATE(create_time) AS day, COUNT(*) AS cnt
FROM orders
WHERE create_time >= NOW() - INTERVAL 30 DAY
GROUP BY day
ORDER BY day;

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十二、快速排除无效数据

SELECT *
FROM orders
WHERE status IN ('PAID', 'SHIPPED')
  AND deleted = 0;

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最后总结

这类业务 SQL 的核心是三点：

1. 写法清晰、能命中索引
2. 更新条件有约束，避免重复或越界
3. 批量操作优先，减少往返成本