clichouse查询报错

Question

遇到一个查询报错的有没有指点一下
加了 n.stationno desc 就报错，不加能查出来数据

SELECT
        n.*,
        n.dc1flow * n.dc1voltage pv1power,
        n.dc2flow * n.dc2voltage pv2power,
        n.dc3flow * n.dc3voltage pv3power,
        n.dc4flow * n.dc4voltage pv4power,
        n.dc5flow * n.dc5voltage pv5power,
        n.dc6flow * n.dc6voltage pv6power,
        n.dc7flow * n.dc7voltage pv7power,
        n.dc8flow * n.dc8voltage pv8power,
        n.sc1flow * n.sc1voltage sc1power,
        n.sc2flow * n.sc2voltage sc2power,
        n.sc3flow * n.sc3voltage sc3power,
        n.sc4flow * n.sc4voltage sc4power,
        n.sc5flow * n.sc5voltage sc5power,
        n.sc6flow * n.sc6voltage sc6power,
        n.sc7flow * n.sc7voltage sc7power,
        n.sc8flow * n.sc8voltage sc8power,
        n.sc9flow * n.sc9voltage sc9power,
        n.sc10flow * n.sc10voltage sc10power
FROM
        mt_ordpowerrecord202503 n
WHERE
        1 = 1
        and n.stationno in ('10202404011133','10202405025906','10202405027621')
        and n.producetime >= 1743150540613
        and n.producetime <= 1743150760216
ORDER BY
   --     n.stationno desc,
        n.inverterno desc,
        n.producetime asc
LIMIT 0,500

Answer 1

让阿豪来帮你解答，本回答参考chatgpt3.5编写提供，如果还有疑问可以评论或留言

这个问题的关键在于您在查询中添加了 `ORDER BY n.stationno DESC` 后出现了报错，而去掉后却能够正常查询出数据。我们将逐步分析这个现象，并给出一些可能的原因和解决方案。

一、查询分析

您提供的 SQL 查询如下（略去不必要的 HTML 标签）：

SELECT 
    n.*, 
    n.dc1flow * n.dc1voltage AS pv1power, 
    n.dc2flow * n.dc2voltage AS pv2power, 
    n.dc3flow * n.dc3voltage AS pv3power, 
    n.dc4flow * n.dc4voltage AS pv4power, 
    n.dc5flow * n.dc5voltage AS pv5power, 
    n.dc6flow * n.dc6voltage AS pv6power, 
    n.dc7flow * n.dc7voltage AS pv7power, 
    n.dc8flow * n.dc8voltage AS pv8power, 
    n.sc1flow * n.sc1voltage AS sc1power, 
    n.sc2flow * n.sc2voltage AS sc2power, 
    n.sc3flow * n.sc3voltage AS sc3power, 
    n.sc4flow * n.sc4voltage AS sc4power, 
    n.sc5flow * n.sc5voltage AS sc5power,
    n.sc6flow * n.sc6voltage AS sc6power, 
    n.sc7flow * n.sc7voltage AS sc7power, 
    n.sc8flow * n.sc8voltage AS sc8power, 
    n.sc9flow * n.sc9voltage AS sc9power, 
    n.sc10flow * n.sc10voltage AS sc10power
FROM 
    mt_ordpowerrecord202503 n
WHERE 
    1 = 1 
    AND n.stationno IN ('10202404011133', '10202405025906', '10202405027621') 
    AND n.producetime >= 1743150540613 
    AND n.producetime <= 1743150760216
ORDER BY 
    n.stationno DESC,
    n.inverterno DESC,
    n.producetime ASC
LIMIT 0, 500;

二、可能的原因和解决方案

1. 字段类型问题：
   • n.stationno 字段可能是一个非字符串类型的字段（如整数），在进行排序时可能会导致冲突。您可以检查这个字段的类型。
2. 数据问题：
   • n.stationno 字段可能没有有效数据（例如 NULL 值），这可能会导致排序时出现异常。您可以先检查目标表中此字段的值。
3. ORDER BY 语句的支持：
   • 一些数据库系统在使用 ORDER BY 限制了字段的选择。如果您在 SELECT 中选择了 n.*，可能会引起数据库在执行时的冗余计算。可以尝试只选择需要的字段，而不是使用 n.*。
4. 调试查询：
   • 可以分步进行测试，逐渐添加条件，看看是哪一部分导致了问题。例如，您可以尝试只使用 n.stationno 排序，再加上 n.inverterno 等。

三、示例修改

SELECT 
    n.stationno, 
    n.inverterno, 
    n.producetime,
    n.dc1flow * n.dc1voltage AS pv1power, 
    -- 添加其他需要的字段
FROM 
    mt_ordpowerrecord202503 n
WHERE 
    n.stationno IN ('10202404011133', '10202405025906', '10202405027621') 
    AND n.producetime >= 1743150540613 
    AND n.producetime <= 1743150760216
ORDER BY 
    n.stationno DESC,
    n.inverterno DESC,
    n.producetime ASC
LIMIT 0, 500;

四、总结

遇到 SQL 查询报错时，可以从以上几个方面进行排查。通过逐步分析和测试，可以找出问题所在并进行修复。希望这些建议对您有所帮助！如有更多问题，请提供错误信息，由此进一步探讨。