Question

我在PHP中选择了这样的SQL：

$sql_GATE  = $conn->query("SELECT  * FROM GATE WHERE st='ff0000' and dataGate between '2018-06-27 00:00:0' and '2018-06-27 23:59:0' order by id desc ");

此代码向我返回大约120000条记录，例如：

1-ff0000-->2018-06-27 18:28:51<br>
2-ff0000-->2018-06-27 18:28:51<br>
3-ff0000-->2018-06-27 18:28:51<br>
13-ff0000-->2018-06-27 18:28:49 .......

如何编写SQL请求，每1分钟仅返回一条记录还是2分钟？因为在一秒钟内大约有3条记录

Answer 1

这里有语法和示例：

SELECT col1, col2, col3, colN, MAX(TimeAndDateColumn)
FROM table
GROUP BY DATE(TameAndDateColumn), HOUR(TimeAndDateColumn), Minute(TimeAndDateColumn)

示例：

SELECT id, latitute, longitude, speed, MAX(`time`)
FROM YourTableName
GROUP BY DATE(`time`), HOUR(`time`), Minute(`time`)

SQL Select，每分钟只有一条记录

1 个答案: