大约有 41,000 项符合查询结果（耗时：0.0422秒） [XML]
Ruby: Easiest Way to Filter Hash Keys?
...answer: Even though this is answer (as of the time of this comment) is the selected answer, the original version of this answer is outdated.
I'm adding an update here to help others avoid getting sidetracked by this answer like I did.
As the other answer mentions, Ruby >= 2.5 added the Hash#sli...
How to subtract 30 days from the current datetime in mysql?
...
SELECT * FROM table
WHERE exec_datetime BETWEEN DATE_SUB(NOW(), INTERVAL 30 DAY) AND NOW();
http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_date-add
...
Return rows in random order [duplicate]
...
SELECT * FROM table
ORDER BY NEWID()
share
|
improve this answer
|
follow
|
...
SQLite select where empty?
In SQLite, how can I select records where some_column is empty?
Empty counts as both NULL and "".
4 Answers
...
How to find elements by class
...
CSS selectors
single class first match
soup.select_one('.stylelistrow')
list of matches
soup.select('.stylelistrow')
compound class (i.e. AND another class)
soup.select_one('.stylelistrow.otherclassname')
soup.select('.st...
How to create a WPF UserControl with NAMED content
... string[] names = e.NewValue.ToString().Split(new char[] { ',' });
if (d is FrameworkElement)
{
((FrameworkElement)d).Name = names[0];
Type t = Type.GetTy...
Simulate CREATE DATABASE IF NOT EXISTS for PostgreSQL?
...k around it from within psql by executing the DDL statement conditionally:
SELECT 'CREATE DATABASE mydb'
WHERE NOT EXISTS (SELECT FROM pg_database WHERE datname = 'mydb')\gexec
The manual:
\gexec
Sends the current query buffer to the server, then treats each column of each row of the query's outpu...
How can I add an item to a SelectList in ASP.net MVC
Basically I am looking to insert an item at the beginning of a SelectList with the default value of 0 and the Text Value of " -- Select One --"
...
'IF' in 'SELECT' statement - choose output value based on column values
...
SELECT id,
IF(type = 'P', amount, amount * -1) as amount
FROM report
See http://dev.mysql.com/doc/refman/5.0/en/control-flow-functions.html.
Additionally, you could handle when the condition is null. In the case of...
Why is there no tuple comprehension in Python?
...because tuple syntax and parenthesis are ambiguous
– Charles Salvia
Jun 5 '13 at 13:14
21
The dif...