大约有 47,000 项符合查询结果（耗时：0.0746秒） [XML]
Find rows that have the same value on a column in MySQL
...
This query will give you a list of email addresses and how many times they're used, with the most used addresses first.
SELECT email,
count(*) AS c
FROM TABLE
GROUP BY email
HAVING c > 1
ORDER BY c DESC
If you want the full rows:
select * from table where email ...
How do I tell Matplotlib to create a second (new) plot, then later plot on the old one?
I want to plot data, then create a new figure and plot data2, and finally come back to the original plot and plot data3, kinda like this:
...
Overriding superclass property with different type in Swift
...properties. Instead you can create an extra variable in the subclass that handles the new class type:
class Chassis {}
class RacingChassis : Chassis {}
class Car {
var chassis = Chassis()
}
class RaceCar: Car {
var racingChassis = RacingChassis()
override var chassis: Chassis {
...
Difference between CPPFLAGS and CXXFLAGS in GNU Make
What's the difference between CPPFLAGS and CXXFLAGS in GNU Make?
4 Answers
4
...
C# Set collection?
...set operations. A set is a collection that contains no duplicate elements, and whose elements are in no particular order...
The capacity of a HashSet(Of T) object is the number of elements that the object can hold. A HashSet(Of T) object's capacity automatically increases as elements are ad...
Objective-C ARC: strong vs retain and weak vs assign
...ew memory management attributes for properties introduced by ARC, strong and weak .
8 Answers
...
How do I resolve git saying “Commit your changes or stash them before you can merge”?
...made some updates on my local machine, pushed them to a remote repository, and now I'm trying to pull the changes to the server and I get the message;
...
Get TFS to ignore my packages folder
... folder. I passionately don't want it source controlled as I'm using NuGet and it's great!
12 Answers
...
encryption/decryption with multiple keys
...
GnuPG does multi-key encryption in standard.
The following command will encrypt doc.txt using the public key for Alice and the public key for Bob. Alice can decrypt using her private key. Bob can also decrypt using his private key.
gpg --encrypt --recipient al...
How to sort my paws?
...nt experiment runs stored as ascii arrays. Rather than try to copy-paste stand-alone code examples into this question, here's a bitbucket mercurial repository with full, stand-alone code. You can clone it with
hg clone https://joferkington@bitbucket.org/joferkington/paw-analysis
Overview
There...