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What should every developer know about databases? [closed]
...fluence that choice;
The concept of coverage (why you shouldn't just write SELECT *);
The difference between a clustered and non-clustered index;
Why more/bigger indexes are not necessarily better;
Why you should try to avoid wrapping filter columns in functions.
Designers should also be aware of ...
Check if a value exists in pandas dataframe index
...ues or the index by appending the ".values" method, e.g.
g in df.<your selected field>.values
g in df.index.values
I find that adding the ".values" to get a simple list or ndarray out makes exist or "in" checks run more smoothly with the other python tools. Just thought I'd toss that out th...
How to allow remote connection to mysql
...SQL and noticed there were multiple root users with different passwords.
select user, host, password from mysql.user;
So in MySQL I set all the passwords for root again and I could finally log in remotely as root.
use mysql;
update user set password=PASSWORD('NEWPASSWORD') where User='root';
fl...
Remove characters from C# string
... where char.IsWhiteSpace(c) || char.IsLetterOrDigit(c)
select c
).ToArray());
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how to use sed, awk, or gawk to print only what is matched?
...
If you want to select lines then strip out the bits you don't want:
egrep 'abc[0-9]+xyz' inputFile | sed -e 's/^.*abc//' -e 's/xyz.*$//'
It basically selects the lines you want with egrep and then uses sed to strip off the bits before an...
How do I access the host machine from the guest machine? [closed]
...ne via NAT;
Right click the network icon in the VM window (bottom-right)
Select "NAT"
Select "Connect"
Wait for the guest OS reconnect to the network
Then, In the Guest OS;
Click Start > Network > Network & Sharing Center
Click "View Status" next to the network connection
Click "Deta...
jQuery scroll to element
...rg/en-US/docs/Web/API/element.scrollIntoView
So all you need to do is: $("selector").get(0).scrollIntoView();
.get(0) is used because we want to retrieve the JavaScript's DOM element and not the JQuery's DOM element.
sha...
AppSettings get value from .config file
...iguration
Go to your Solution Explorer and right click on References and select Add reference. Select the Assemblies tab and search for Configuration.
Here is an example of my App.config:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<startup>
<suppo...
How can I extract embedded fonts from a PDF as valid font files?
...or FontForge:
Use the "Open Font" dialogbox used when opening files.
Then select "Extract from PDF" in the filter section of dialog.
Select the PDF file with the font to be extracted.
A "Pick a font" dialogbox opens -- select here which font to open.
Check the FontForge manual. You may need to fol...
Best way to give a variable a default value (simulate Perl ||, ||= )
...
return true;
} else {
return false;
}
}
function select_defined(){
$l = func_num_args();
$a = func_get_args();
for ($i=0; $i<$l; $i++){
if ($a[$i]) return $a[$i];
}
}
Examples:
// $foo ||= $bar;
set_unless_defined($foo, $bar);
//$foo = $baz ||...