mysql中的一天总结答案

【问题标题】：Summary of the day in mysqlmysql中的一天总结
【发布时间】：2017-12-26 13:42:53
【问题描述】：

我在创建提供按日期分组的数据的查询时遇到了一些问题。我在*中阅读了一些示例，但无法做到。谁能帮我理解如何做到这一点？这是我的数据：

veiculo_id | data_pacote              | hodometro_inicial | hodometro_final | velocidade

1125370    | '2017-11-13 22:53:12-02' | 6673657           | 6673657         | '20'
1125370    | '2017-11-13 22:53:11-02' | 42526             | 42526           | '35' 
1125370    | '2017-11-13 22:53:09-02' | 2532721           | 2532721         | '47'
1125370    | '2017-11-13 22:53:05-02' | 386358            | 386358          | '0'
1125370    | '2017-11-14 12:53:03-02' | 273085            | 273085          | '45'
1125370    | '2017-11-14 12:53:02-02' | 2004482           | 2004482         | '43'

我需要为每个 veiculo_id(dadtveioid) 获取当天的摘要，这将是当天 dadtodometro 的最大值和最小值以及当天的平均 dadtvelocidade。结果是这样的：

veiculo_id | data_pacote   | hodometro_inicial | hodometro_final | velocidade

1125370    | '2017-11-13'  | 6673657           | 42526           | '51'
1125370    | '2017-11-14'  | 2004482           | 273085          | '44'

我现在拥有的是这样的：

SELECT dadtveioid AS veiculo_id,
       dadtdt_pacote AS data_pacote, 
       min(dadtodometro) AS hodometro_inicial, 
       max(dadtodometro) AS hodometro_final, 
       sum(dadtvelocidade) AS velocidade 
FROM dados_telemetria  
GROUP BY dadtveioid, dadtdt_pacote 
ORDER BY dadtdt_pacote DESC

谢谢。

【问题讨论】：

使用 GROUP BY dadtveioid, date(dadtdt_pacote) 以及 date(dadtdt_pacote) AS data_pacote
感谢@BerndBuffen，它成功了。我以前试过这个，但它没有用，我想我错过了一些东西。

标签： mysql sql postgresql

【解决方案1】：

您可以在 postgreSQL 中尝试以下代码

WITH dados_telemetria AS (
SELECT 1125370::int AS veiculo_id, '2017-11-13 22:53:12-02'::TIMESTAMP AS data_pacote, 6673657::int AS hodometro_inicial, 6673657::int AS hodometro_final,'20'::int AS velocidade
UNION ALL
SELECT 1125370::int AS veiculo_id, '2017-11-13 22:53:11-02'::TIMESTAMP AS data_pacote, 42526::int AS hodometro_inicial,   42526::int AS hodometro_final, '35'::int AS velocidade
UNION ALL
SELECT 1125370::int AS veiculo_id, '2017-11-13 22:53:09-02'::TIMESTAMP AS data_pacote, 2532721::int AS hodometro_inicial, 2532721::int AS hodometro_final,'47'::int AS velocidade
UNION ALL
SELECT 1125370::int AS veiculo_id, '2017-11-13 22:53:05-02'::TIMESTAMP AS data_pacote, 386358::int AS hodometro_inicial,  386358::int AS hodometro_final, '0'::int AS velocidade
UNION ALL
SELECT 1125370::int AS veiculo_id, '2017-11-14 12:53:03-02'::TIMESTAMP AS data_pacote, 273085::int AS hodometro_inicial,  273085::int AS hodometro_final, '45'::int AS velocidade
UNION ALL
SELECT 1125370::int AS veiculo_id, '2017-11-14 12:53:02-02'::TIMESTAMP AS data_pacote, 2004482::int AS hodometro_inicial, 2004482::int AS hodometro_final,'43'::int AS velocidade
)
SELECT veiculo_id,
       DATE(data_pacote) AS data_pacote,
       min(hodometro_inicial) AS min_hodometro_inicial, 
       max(hodometro_inicial) AS max_hodometro_inicial, 
       min(hodometro_final) AS min_hodometro_final, 
       max(hodometro_final) AS max_hodometro_final, 
       sum(velocidade) AS velocidade 
FROM 
    dados_telemetria  
GROUP BY 
    veiculo_id,
    DATE(data_pacote)
ORDER BY data_pacote DESC

你会得到以下结果

veiculo_id data_pacote min_hodometro_inicial max_hodometro_inicial min_hodometro_final max_hodometro_final velocidade 
---------- ----------- --------------------- --------------------- ------------------- ------------------- ---------- 
1125370    2017-11-13  42526                 6673657               42526               6673657             102        
1125370    2017-11-14  273085                2004482               273085              2004482             88

【讨论】：