英文:
NOW() can't be used in query (it doesn't exist)
问题
在我的Go代码中，我有这行代码：
rows, err := conn.Query(`
SELECT id, name, lang, deleted_at, read
FROM categories
WHERE deleted_at < NOW()
`)
当我运行这段代码时，我从PostgreSQL得到一个错误：
pq: function now() does not exist
（pq是我使用的Go驱动程序）
使用CURRENT_TIMESTAMP也会引发错误。它说列current_timestamp不存在。在psql（命令行）中直接使用NOW()不会引发该错误，一切正常运行。
对于为什么我无法在我的Go应用程序中发送查询时使用NOW()或CURRENT_TIMESTAMP，有什么想法吗？
英文:
In my Go code, I have this line of code:
rows, err := conn.Query(`
SELECT id, name, lang, deleted_at, read
FROM categories
WHERE deleted_at < NOW()
`)
When I run this, I get an error from PostgreSQL:
pq: function  now() does not exist
(pq is the Go driver that I use)
Using CURRENT_TIMESTAMP also provokes an error. It says that the column current_timestamp does not exist. Using NOW() directly in psql (command line) does not provoke that error and everything works fine.
Any idea on why I can't use NOW() nor CURRENT_TIMESTAMP when sending a query from my Go app?
答案1
得分: 1
我的键盘上的右Alt键卡住了，我没有注意到。这导致我在按下空格键时插入了不可断空格。PostgreSQL可能将不可断空格解释为函数名称的一部分。
改为插入普通空格解决了这个问题。
英文:
My right alt key on my keyboard got stuck without me noticing. That made me insert non-breakable spaces when pressing the space bar. PostgreSQL probably interpreted the non-breakable space as a character that is part of the function's name.
Inserting regular spaces instead solved the issue.
答案2
得分: 0
根据我所看到的，你的查询没有问题。当实际存在该函数但期望的值类型不同时，PostgreSQL也可能会抛出函数未找到的错误。
函数now()返回的是带有时区的时间戳。如果deleted_at列的类型与其不同，你可能需要将deleted_at或now()的输出进行类型转换。
英文:
As far as I can see there is nothing wrong with your query. PostgreSQL can throw function not found at you also when the function actually exists but a different value type is expected.
The function now() returns timestamp with time zone. If the column deleted_at is not of the same type, you might need to cast either deleted_at or the output from now().
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论