lastval() bigint 返回当前会话里最近一次nextval返回的数值。这个函数等效于currval,只是它不用序列名为参数,它抓取当前会话里面最近一次nextval使用的序列。如果当前会话还没有调用过nextval,那么调用lastval将会报错。 setval(regclass, bigint) bigint 重置序列对象的计数器数值。设置序列的last_value字段为指定...
Appendix C.SQL 关键字 Table C-1列出了所由在 SQL 标准和PostgreSQL 8.1 里是关键字的记号。 你可以在Section 4.1.1里找到相关的背景信息。 SQL 里有保留字(保留)和非保留字之分。根据标准, 保留字是那些真正的关键字;我们决不能用它们做标识符。 非保留字只是在特定的环境里有特殊的含义,而在其它环境里...
date_trunc: 这个函数用于截断日期到指定的单位(例如,'month'表示月份)。 INTERVAL: 这个关键字用于表示时间间隔。 应用场景 这个查询可以用于需要按周统计数据的场景,例如: 按周统计销售额 按周统计用户活跃度 按周生成报告 可能遇到的问题及解决方法 日期边界问题: 如果一个月的第一天不是周一,或者最后一天不是周...
count(*) as count where activated_at notnull ) 这是每周激活的供应商的查询计数数我需要把一周的开始日期从星期一改为星期六。类似的文章如how to change the first day of the week in PostgreSQL或Making Postgres date_trunc() use 浏览17提问于2020-08-20得票数 0 1回答 如何将Date.new...
env.put("quarter", (cal.get(Calendar.MONTH) / 3) + 1); env.put("month", cal.get(Calendar.MONTH) + 1); env.put("week", cal.get(Calendar.WEEK_OF_YEAR)); env.put("day", cal.get(Calendar.DATE)); env.put("hour", cal.get(Calendar.HOUR_OF_DAY)); ...
) 🇩🇪 Andreas Scherbaum shares an update on PostgreSQL Berlin's recent meetup. 🇳🇱 Meanwhile, Pavlo Golub shares how PGDay Lowlands 2024 went last month.Is pg_dump a 'Backup' Tool?— I’ve used pg_dump to make backups, and probably so have you, but the docs seem keen to ...
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There is so much goodness in PostgreSQL 17, which hit code freeze last month in April and is expected to GA later this calendar year, usually in Sep or Oct—with a beta release that typically lands in July or August. Highlights of theover 300 commitsto PG17 authored...
We’ll see no change for our query from a month or two ago, but if we try to query a more recent time, we won’t have any data. If we want it up to date with more recent data, we’ll need to run: REFRESH MATERIALIZED VIEW ohlc_mat; ...
Overview of the Postgres work done at Microsoft in the last year, both on Azure & in the open source community.