SQL 检测脚本

1、基本介绍

SQL 检测脚本通常指一段用 SQL 或相关工具编写的脚本，用来自动检查数据库中的某些问题

2、演示

（1）检测目标

检查一个电商库的常见问题，假设有张订单表 orders

sql 复制代码

CREATE TABLE orders (
    id          BIGINT PRIMARY KEY AUTO_INCREMENT,
    user_id     BIGINT NOT NULL,
    amount      DECIMAL(10,2) NOT NULL,
    status      VARCHAR(20) NOT NULL,
    created_at  DATETIME NOT NULL
);

（2）检测脚本

检查主键重复（数据质量）：正常应返回 0 行。有结果说明主键被破坏

sql 复制代码

SELECT id, COUNT(*) AS cnt
FROM orders
GROUP BY id
HAVING cnt > 1;

检查金额异常（业务规则）：找出金额为负或异常巨大的订单

sql 复制代码

SELECT *
FROM orders
WHERE amount <= 0 OR amount > 1000000;

检查状态值是否非法（枚举校验）：返回空表示所有状态都合法

sql 复制代码

SELECT DISTINCT status
FROM orders
WHERE status NOT IN ('pending', 'paid', 'shipped', 'done', 'cancelled');

检查孤儿数据（外键完整性）：找出下了单但用户不存在的脏数据

sql 复制代码

SELECT o.id, o.user_id
FROM orders o
LEFT JOIN users u ON o.user_id = u.id
WHERE u.id IS NULL;

检查慢查询 / 长事务（性能）：找出执行超过 60 秒的查询

sql 复制代码

SELECT id, user, time, state, info
FROM information_schema.processlist
WHERE command != 'Sleep'
  AND time > 60;

检查表空间占用（容量）：看哪张表最大，是否异常增长

sql 复制代码

SELECT
    table_name,
    ROUND((data_length + index_length) / 1024 / 1024, 2) AS size_mb
FROM information_schema.tables
WHERE table_schema = 'your_db'
ORDER BY size_mb DESC
LIMIT 10;

（3）实际使用

实际使用时，通常会把上面这些 SQL 写进一个 SQL 文件，例如，check_orders.sql

sql 复制代码

SELECT '主键重复' AS check_item, COUNT(*) AS problem_count
FROM (SELECT id FROM orders GROUP BY id HAVING COUNT(*) > 1) t;

SELECT '金额异常' AS check_item, COUNT(*) AS problem_count
FROM orders WHERE amount <= 0 OR amount > 1000000;

SELECT '状态非法' AS check_item, COUNT(*) AS problem_count
FROM orders
WHERE status NOT IN ('pending','paid','shipped','done','cancelled');

SELECT '孤儿订单' AS check_item, COUNT(*) AS problem_count
FROM orders o LEFT JOIN users u ON o.user_id = u.id
WHERE u.id IS NULL;

shell 复制代码

mysql -u root -p 【数据库名】 < check_orders.sql

（4）shell 自动跑 + 告警

写进一个 shell 脚本，例如，check_orders.sh

shell 复制代码

#!/bin/bash
set -euo pipefail

DB_HOST="127.0.0.1"
DB_USER="root"
DB_PASS="your_password"
DB_NAME="your_db"
SQL_FILE="/opt/scripts/check_orders.sql"
LOG_FILE="/var/log/check_orders.log"
ALERT_WEBHOOK="https://your-webhook-url" # 告警接收地址，例如，钉钉、企微
ALERT_THRESHOLD=1 # 问题数达到该值就触发告警，1 表示只要有问题就告警

# 执行检测 SQL，-N 不输出列名，-B 制表符分隔，方便逐行解析
RESULT=$(mysql -h"$DB_HOST" -u"$DB_USER" -p"$DB_PASS" "$DB_NAME" -N -B < "$SQL_FILE")

ALERT_MSG=""
TOTAL=0

while IFS=$'\t' read -r item count; do
    [ -z "$item" ] && continue
    echo "$(date '+%F %T') [$item] = $count" >> "$LOG_FILE"
    if [ "$count" -ge "$ALERT_THRESHOLD" ]; then
        ALERT_MSG="${ALERT_MSG}${item}: ${count} 条\n"
        TOTAL=$((TOTAL + count))
    fi
done <<< "$RESULT"

# 有问题才发告警，没问题只记日志
if [ "$TOTAL" -gt 0 ]; then
    MSG="【订单表检测告警】\n${ALERT_MSG}请及时处理。"
    curl -s -X POST "$ALERT_WEBHOOK" \
        -H 'Content-Type: application/json' \
        -d "{\"msgtype\":\"text\",\"text\":{\"content\":\"$MSG\"}}"
    echo "$(date '+%F %T') 已发送告警" >> "$LOG_FILE"
else
    echo "$(date '+%F %T') 全部正常" >> "$LOG_FILE"
fi

赋予可执行权限

shell 复制代码

chmod +x /opt/scripts/check_orders.sh

测试 shell 脚本

shell 复制代码

/opt/scripts/check_orders.sh
cat /var/log/check_orders.log

配置定时任务

shell 复制代码

crontab -e

shell 复制代码

0 * * * * /opt/scripts/check_orders.sh >/dev/null 2>&1