您好,登錄后才能下訂單哦!
這篇文章主要介紹PostgreSQL timestamp有哪些坑要注意一下,文中介紹的非常詳細(xì),具有一定的參考價(jià)值,感興趣的小伙伴們一定要看完!
NodeJS:UTC+08
PostgreSQL:UTC+00
timestampTest.js const { Client } = require('pg') const client = new Client() client.connect() let sql = `` client.query(sql, (err, res) => { console.log(err ? err.stack : res.rows[0].datetime) client.end() })
測(cè)試輸入數(shù)據(jù)為1514736000(UTC時(shí)間2017-12-31 16:00:00,北京時(shí)間2018-01-01 00:00:00)
1、timezone=UTC
BEGIN; SET TIME ZONE 'UTC'; SELECT to_timestamp(1514736000) as datetime; END;
直接查詢:2017-12-31 16:00:00+00YES
pg查詢:2017-12-31T16:00:00.000ZYES
2、timezone=PRC
BEGIN; SET TIME ZONE 'PRC'; SELECT to_timestamp(1514736000) as datetime; END;
直接查詢:2018-01-01 00:00:00+08NO
pg查詢:2017-12-31T16:00:00.000ZYES
PostgreSQL官方文檔對(duì)timestamp的一個(gè)描述
詳見(jiàn):8.5.1.3. Time Stamps
In a literal that has been determined to be timestamp without time zone, PostgreSQL will silently ignore any time zone indication. That is, the resulting value is derived from the date/time fields in the input value, and is not adjusted for time zone.
使用to_timestamp進(jìn)行時(shí)間轉(zhuǎn)換且DB時(shí)區(qū)非UTC時(shí),寫(xiě)入**timestamp without time zone**類(lèi)型的COLUMN則會(huì)與預(yù)期結(jié)果不符。
1、timezone=UTC,timestamp with timezone
BEGIN; SET TIME ZONE 'UTC'; SELECT TIMESTAMP WITH TIME ZONE '2017-12-31T16:00:00+00' as datetime; END;
直接查詢:2017-12-31 16:00:00+00YES
pg查詢:2017-12-31T16:00:00.000ZYES
2、timezone=UTC,timestamp without timezone
BEGIN; SET TIME ZONE 'UTC'; SELECT TIMESTAMP '2017-12-31T16:00:00+00' as datetime; END;
直接查詢:2017-12-31 16:00:00YES
pg查詢:2017-12-31T08:00:00.000ZNO
3、timezone=PRC,timestamp with timezone
BEGIN; SET TIME ZONE 'PRC'; SELECT TIMESTAMP WITH TIME ZONE '2017-12-31T16:00:00+00' as datetime; END;
直接查詢:2018-01-01 00:00:00+08YES
pg查詢:2017-12-31T16:00:00.000ZYES
4、timezone=PRC,timestamp without timezone
BEGIN; SET TIME ZONE 'PRC'; SELECT TIMESTAMP '2017-12-31T16:00:00+00' as datetime; END;
直接查詢:2017-12-31 16:00:00YES
pg查詢:2017-12-31T08:00:00.000ZNO
據(jù)以上結(jié)果可判定:
使用pg查詢**timestamp without time zone**類(lèi)型的COLUMN時(shí),會(huì)將數(shù)據(jù)庫(kù)存儲(chǔ)的時(shí)間當(dāng)做北京時(shí)間而非UTC時(shí)間,與數(shù)據(jù)庫(kù)時(shí)區(qū)沒(méi)有關(guān)系。
網(wǎng)上類(lèi)似問(wèn)題的解決辦法是將DB時(shí)區(qū)改為UTC+08。
原理:寫(xiě)入DB的時(shí)間實(shí)際為北京時(shí)間,pg庫(kù)恰好是當(dāng)做北京時(shí)間讀取,所以時(shí)間戳就不會(huì)出問(wèn)題了。
假如應(yīng)用部署在不同的地域,使用timestamp without time zone存儲(chǔ)timestamp這樣的設(shè)計(jì)簡(jiǎn)直是災(zāi)難。
不要用timestamp without time zone存儲(chǔ)timestamp!
不要用timestamp without time zone存儲(chǔ)timestamp!
不要用timestamp without time zone存儲(chǔ)timestamp!
補(bǔ)充:pg查詢時(shí)間間隔(timestamp類(lèi)型)
create_date timestamp(6) without time zone
1.從2015-10-12到2015-10-13 之間的4點(diǎn)到9點(diǎn)的數(shù)據(jù)
select * from schedule where create_date between to_date('2015-10-12','yyyy-MM-dd') and to_date('2015-10-13','yyyy-MM-dd') and EXTRACT(hour from create_date) between 4 and 9;
結(jié)果:
2.2015-10-12五點(diǎn)的數(shù)據(jù)
select * from schedule where hospital_id='syzyyadmin' and date_trunc('hour',create_date)=to_timestamp('2015-10-12 05','YYYY-MM-DD HH24')
結(jié)果:
以上是“PostgreSQL timestamp有哪些坑要注意一下”這篇文章的所有內(nèi)容,感謝各位的閱讀!希望分享的內(nèi)容對(duì)大家有幫助,更多相關(guān)知識(shí),歡迎關(guān)注億速云行業(yè)資訊頻道!
免責(zé)聲明:本站發(fā)布的內(nèi)容(圖片、視頻和文字)以原創(chuàng)、轉(zhuǎn)載和分享為主,文章觀點(diǎn)不代表本網(wǎng)站立場(chǎng),如果涉及侵權(quán)請(qǐng)聯(lián)系站長(zhǎng)郵箱:is@yisu.com進(jìn)行舉報(bào),并提供相關(guān)證據(jù),一經(jīng)查實(shí),將立刻刪除涉嫌侵權(quán)內(nèi)容。