The function GETDATE() returns a different value from time to time, so it is not a constant expression.*/--IF @EndDate is null--SET @EndDate = getdate()--orSET@EndDate=Coalesce(@EndDate,GetDate()) ;WITHcteRange(DateRange)AS(SELECTCAST(@StartDateASDATE)UNIONALLSELECTCASEWHEN@Incremen...
actor.name没有索引，此时创建了张临时表来distinctmysql> explain select distinct name from actor;film.name建立了idx_name索引，此时查询时extra是using index,没有用临时表mysql> explain select distinct name from film;Using filesortmysql 会对结果使用一个外部索引排序，而不是按索引次序从表里读取行。此时mys...
select count(*) from ytt_pt1 where log_date >='2018-01-01' and log_date <'2019-01-01'; 同样是分区表 ytt_pt1_month1 ,基于这张表的SQL语句如下: select count(*) from ytt_pt1_month1 where log_date in ('2020-01-01','2020-01-02','...
SELECT [Date]= @startDateTime UNION ALL SELECT [Date] + 1 FROM Dates WHERE [Date] + 1 <= @endDateTime ), DateRange([Date], [StartDateTime], [EndDateTime]) AS ( SELECT [Date], DATEADD(DAY, DATEDIFF(DAY, 0, [Date]), 0), DATEADD(SECOND, -1, DATEADD(DAY, DATEDIFF(DAY, 0, [...
SQL查询语句用于从零个或多个表中检索数据行,其可以包含子查询语句,还可以用UNION等将多个SELECT语句组合起来获取结果,也可以用WITH子句定义在SELECT中可访问的公共表表达式(CTE,Common Table Expressions)。 OLTP领域追求SQL查询语句简单高效,很多功能特性都会避免使用,甚至不惜拆分多次执行以最大化数据库系统的并发能力;...
查询并聚合一个「给定长度的时间范围的数据」,是时序数据中常见的一种查询模式。例如 PromQL 中的 Range selector,就原生地支持了这种时序查询。但对于通用的数据库查询语言 SQL ,这类时序查询很难通过原生的 S…
现在假设你修改窗口为RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW,会发生什么: 1SELECT2t.OrderYear,3t.OrderMonth,4t.TotalDue,5SUM(t.TotalDue)OVER(ORDERBYt.OrderYear, t.OrderMonth RANGEBETWEENUNBOUNDED PRECEDINGANDCURRENTROW)AS'RunningTotal'6FROM7(8SELECT9YEAR(OrderDate)AS'OrderYear',10MONTH...
当我按日期查询一条记录时,如果当天没有记录,我感兴趣的是按日期计算的前一条记录。例如: SELECT * FROM rates WHERE date <= $mydate ORDER BY date DESC LIMIT 1; 给定一个日期列表,我如何构造一个查询来返回与每个日期 浏览19提问于2019-10-10得票数 1 回答已采纳...
import { getConnection } from "typeorm"; async function searchByDateRange(startDate: Date, endDate: Date) { const connection = getConnection(); const queryBuilder = connection.createQueryBuilder(); const result = await queryBuilder .select() .from("your_table_name") .where("date_column ...
select user_profiles.user_id, event_params.{event_name}.{event_param_name} from events where event = 'sogo' and event_date > '2020-01-01' order by event_time desc limit 10; Plain 查询一段时间内用户购买数量分布情况 select case when amount > 10 then 'x>10' when amount >5 and amoun...