大约有 40,000 项符合查询结果（耗时：0.0269秒） [XML]
MySQL COUNT DISTINCT
...
Select
Count(Distinct user_id) As countUsers
, Count(site_id) As countVisits
, site_id As site
From cp_visits
Where ts >= DATE_SUB(NOW(), INTERVAL 1 DAY)
Group By site_id
...
How to resize a VirtualBox vmdk file
... want to download gparted iso and boot from that iso to resize your drive (select the iso from within the virtualbox settings).
P.S. If your new size is too small, you'll get the same error even with your new vdi file.
shar...
Xcode 4 - “Valid signing identity not found” error on provisioning profiles on a new Macintosh insta
...machine, launch Xcode and do this:
Open the Organizer (Shift-Command-2).
Select the Devices tab.
Choose Developer Profile in the upper-left corner under LIBRARY, which may be under the heading library or under a heading called TEAMS.
Choose Export near the bottom left side of
the window. Xcode as...
Pandas conditional creation of a series/dataframe column
...
If you only have two choices to select from:
df['color'] = np.where(df['Set']=='Z', 'green', 'red')
For example,
import pandas as pd
import numpy as np
df = pd.DataFrame({'Type':list('ABBC'), 'Set':list('ZZXY')})
df['color'] = np.where(df['Set']=='Z', ...
Inspect hovered element in Chrome?
...er over the element to bring up the tooltip, right click as if you were to select 'Inspect Element'. Leaving that context menu open, move the focus over to the dev tools. The html for the tooltip should show up next to the element its a tooltip for in the HTML. Then you can look at it as if it were ...
Differences between MySQL and SQL Server [closed]
...mplementations.
For example, take a look at the top-n section. In MySQL:
SELECT age
FROM person
ORDER BY age ASC
LIMIT 1 OFFSET 2
In SQL Server (T-SQL):
SELECT TOP 3 WITH TIES *
FROM person
ORDER BY age ASC
share
...
How do you perform a CROSS JOIN with LINQ to SQL?
... it.
var combo = from p in people
from c in cars
select new
{
p.Name,
c.Make,
c.Model,
c.Colour
};
share
...
How do I remove the first characters of a specific column in a table?
...
SELECT RIGHT(MyColumn, LEN(MyColumn) - 4) AS MyTrimmedColumn
Edit:
To explain, RIGHT takes 2 arguments - the string (or column) to operate on, and the number of characters to return (starting at the "right" side of the stri...
IntelliJ: Viewing diff of all changed files between local and a git commit/branch
... new UI, click on Show Diff with Working Tree
Next a window will pop up. Select Files and press cmd + d
Another window which shows diff. You can perform many different types of diff. Use cmd + shift + ] and cmd + shift + [ to shift between files.
Diff Tip: IntelliJ provides advanced diff feat...
How to fix Python indentation
... do this:
$ # see what changes it would make
$ autopep8 path/to/file.py --select=E101,E121 --diff
$ # make these changes
$ autopep8 path/to/file.py --select=E101,E121 --in-place
Note: E101 and E121 are pep8 indentation (I think you can simply pass --select=E1 to fix all indentation related issue...