select sum(max(TRUNCATE(cast(t0.disk_space_utilization as decimal(30,8)), 0))) over ( order by max(TRUNCATE(cast(t0.disk_space_utilization as decimal(30,8)), 0)))*1.0/100 as calc from (SELECT a.sync_time, a.equipment_monitor_id, a.equipment_id, a.cpu_load, a.memory_load, a.disk_space, a.disk_space_utilization, a.network_card_throughput, a.control_unit_temperature FROM nec_equipment_monitor_statistics a order by a.sync_time) t0 where (t0.equipment_id='IT-A01-32' AND str_to_date(t0.sync_time,'%Y-%m-%d %H:%i:%s')>=str_to_date('20230519','%Y%m%d') and str_to_date(t0.sync_time,'%Y-%m-%d %H:%i:%s')<str_to_date('20230520','%Y%m%d'))

这一个 SQL 查询语句，它的作用是计算指定设备在指定时间范围内的磁盘使用率的加权平均值。具体来说，它对设备每个同步时间点的磁盘使用率取一个小数点后8位的最大值，然后按照这个值排序，再计算排序后的值的累加和并除以100，得到最终的加权平均值。这个查询语句中的条件是设备编号为 'IT-A01-32'，同步时间在 '2023-05-19' 至 '2023-05-20' 之间。

相关问题

优化以下SQL语句使该语句可以在MySQL5.0中可以运行：select sum(max(TRUNCATE(cast(t0.disk_space_utilization as decimal(30,8)), 0))) over ( order by max(TRUNCATE(cast(t0.disk_space_utilization as decimal(30,8)), 0)))*1.0/100 as calc from (SELECT a.sync_time, a.equipment_monitor_id, a.equipment_id, a.cpu_load, a.memory_load, a.disk_space, a.disk_space_utilization, a.network_card_throughput, a.control_unit_temperature FROM nec_equipment_monitor_statistics a order by a.sync_time) t0 where (t0.equipment_id='IT-A01-32' AND str_to_date(t0.sync_time,'%Y-%m-%d %H:%i:%s')>=str_to_date('20230519','%Y%m%d') and str_to_date(t0.sync_time,'%Y-%m-%d %H:%i:%s')<str_to_date('20230520','%Y%m%d'))

MySQL 5.0 不支持窗口函数和子查询中的 ORDER BY 子句，因此需要对该 SQL 语句进行重构。我们可以使用 GROUP BY 和 JOIN 来替代窗口函数和子查询中的 ORDER BY 子句。具体来说，我们可以将子查询中的 ORDER BY 移到外部查询中，并使用 GROUP BY 对结果进行分组，然后使用 JOIN 将分组结果与原表进行连接。下面是重构后的 SQL 语句：

SELECT SUM(MAX(TRUNCATE(CAST(t.disk_space_utilization AS DECIMAL(30,8)), 0))) * 1.0/100 AS calc
FROM (
    SELECT a.equipment_id, MAX(TRUNCATE(CAST(a.disk_space_utilization AS DECIMAL(30,8)), 0)) AS max_utilization
    FROM nec_equipment_monitor_statistics a
    WHERE a.equipment_id = 'IT-A01-32'
        AND STR_TO_DATE(a.sync_time,'%Y-%m-%d %H:%i:%s') BETWEEN '2023-05-19 00:00:00' AND '2023-05-20 00:00:00'
    GROUP BY a.equipment_id
) t
JOIN nec_equipment_monitor_statistics s ON t.equipment_id = s.equipment_id AND TRUNCATE(CAST(s.disk_space_utilization AS DECIMAL(30,8)), 0) = t.max_utilization;

需要注意的是，由于 MySQL 5.0 不支持 CAST 函数的 DECIMAL 类型参数，因此需要将 DECIMAL(30,8) 修改为 DECIMAL。

SELECT a.project_name AS projectName, a.order_no AS orderNo, workHourPlan AS workHourPlan FROM t_project_plan_management a WHERE a.reserve3 != '1' workHourPlan IN ( SELECT SUM(TRUNCATE( b.work_hour , 2 ) ) FROM t_work_hour b WHERE b.order_no = a.order_no )错在哪

在这个 SQL 语句中，您的 WHERE 子句中缺少一个逻辑运算符。应该在 `a.reserve3 != '1'` 之后添加 `AND` 连接符。

这是修改后的 SQL 语句：

SELECT 
    a.project_name AS projectName, 
    a.order_no AS orderNo, 
    workHourPlan AS workHourPlan 
FROM 
    t_project_plan_management a 
WHERE 
    a.reserve3 != '1' 
    AND workHourPlan IN (
        SELECT 
            SUM(TRUNCATE(b.work_hour, 2)) 
        FROM 
            t_work_hour b 
        WHERE 
            b.order_no = a.order_no
    )

这样修改后，SQL 语句就可以正确执行了。