解释下BETWEEN $__timeFrom() AND $__timeTo()

BETWEEN $__timeFrom() AND $__timeTo() 是一个用于时间范围查询的函数。它是 Grafana 可视化工具中的一个模板变量，$__timeFrom() 返回当前查询的起始时间戳，$__timeTo() 返回当前查询的结束时间戳。这个函数可以用于构建 SQL 查询语句，例如：

SELECT * FROM mytable WHERE timestamp BETWEEN $__timeFrom() AND $__timeTo()

这个查询语句会查询 mytable 表中在当前时间范围内的记录。这个函数可以方便地构建动态的时间范围查询语句，避免了手动输入时间范围的麻烦。

相关问题

代码报错syntax error at or near "BETWEEN"，代码如下SELECT $__timeGroupAlias("my_time_field", '1h'), MAX(PARAMVALUE)FROM ( SELECT to_number(paramvalue,'99.99') as paramvalue, CAST(starttime AS timestamp) as "my_time_field" FROM s01mplc.r_eqp_rawdata WHERE line='S013CBIM01' AND $__timeFilter(CAST(starttime AS timestamp)) AND pt_insert_date=to_char(now(), 'YYYYMMDD') AND parameter like 'FilmDownTime0%' ORDER BY starttime DESC) AGROUP BY 1

根据您提供的查询语句，我发现在时间过滤器 `$__timeFilter(CAST(starttime AS timestamp))` 之后，您没有使用 `BETWEEN` 关键字来指定时间范围，导致该语句在 `MAX(PARAMVALUE)` 之前的部分缺少时间约束。

您可以尝试修改该查询语句，将时间范围指定为 `BETWEEN` 关键字之间的两个时间戳，例如：

SELECT $__timeGroupAlias("my_time_field", '1h'), MAX(PARAMVALUE) FROM (
  SELECT to_number(paramvalue,'99.99') as paramvalue, CAST(starttime AS timestamp) as "my_time_field"
  FROM s01mplc.r_eqp_rawdata
  WHERE line='S013CBIM01'
    AND CAST(starttime AS timestamp) BETWEEN $__timeFrom() AND $__timeTo()
    AND pt_insert_date=to_char(now(), 'YYYYMMDD')
    AND parameter like 'FilmDownTime0%'
  ORDER BY starttime DESC
) A
GROUP BY 1

这里我使用了 `$__timeFrom()` 和 `$__timeTo()` 函数来获取时间范围，您也可以根据需要修改这些函数来指定自己的时间范围。

mysql push_time between and

The "between" keyword in MySQL is used to filter data based on a range of values. When used with "push_time", it filters data based on a range of date and time values.

For example, the following query retrieves all records where the "push_time" value is between January 1st, 2021 at 12:00 AM and January 31st, 2021 at 11:59 PM:

SELECT * FROM table_name WHERE push_time BETWEEN '2021-01-01 00:00:00' AND '2021-01-31 23:59:59';

This query will retrieve all records from the "table_name" table where the "push_time" value falls within the specified range. Note that the date and time values are formatted as strings in the 'YYYY-MM-DD HH:MM:SS' format.