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SQL Server IN vs. EXISTS Performance
...execution operation, to get their results.
An example:
Query 1 ( plan )
select * from dt where dt.customer in (select c.code from customer c where c.active=0)
Query 2 ( plan )
select * from dt where exists (select 1 from customer c where c.code=dt.customer and c.active=0)
...
How do I get only directories using Get-ChildItem?
...eturned by Get-ChildItem has a "base" property, PSIsContainer. You want to select only those items.
Get-ChildItem -Recurse | ?{ $_.PSIsContainer }
If you want the raw string names of the directories, you can do
Get-ChildItem -Recurse | ?{ $_.PSIsContainer } | Select-Object FullName
For PowerSh...
C# Linq Group By on multiple columns [duplicate]
... c.School,
c.Friend,
c.FavoriteColor,
} into gcs
select new ConsolidatedChild()
{
School = gcs.Key.School,
Friend = gcs.Key.Friend,
FavoriteColor = gcs.Key.FavoriteColor,
Children = gcs.ToList(),
};
var consolidatedChildren =
...
Java compiler level does not match the version of the installed Java project facet
...he Project Properties dialog.
There is a Project Facets item on the left, select it, look for the Java facet on the list, choose which version you want to use for the project and apply.
share
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How to move the cursor word by word in the OS X Terminal
...e sequences for you:
Open Terminal preferences (cmd+,);
At Settings tab, select Keyboard and double-click ⌥ ← if it's there, or add it if it's not.
Set the modifier as desired, and type the shortcut key in the box: esc+B, generating the text \033b (you can't type this text manually).
Repeat fo...
Can I do a partial revert in GIT
... can also do git add -p to start an interactive session that allows you to selectively add chunks of files, instead of entire files. (There's also git reset -p to selectively unstage changes. Good to know, but probably not what you want in this scenario.)
– Stéphan Kochen
...
Trim trailing spaces in Xcode
...
You can create a script and bind it to a keyboard shortcut:
Select Scripts Menu > Edit User Scripts...
Press the + button and select New Shell Script
Give it a name like "Strip Trailing Spaces", and give it a shortcut like ⌃⇧R.
Set Input to "Selection" and Output to "Replace Se...
How to display the function, procedure, triggers source code in postgresql?
...
For function:
you can query the pg_proc view , just as the following
select proname,prosrc from pg_proc where proname= your_function_name;
Another way is that just execute the commont \df and \ef which can list the functions.
skytf=> \df
...
What is the use of the square brackets [] in sql statements?
...
sql also uses square brackets in the like-operator of a select query to limit results using regular expressions. codeproject.com/Articles/33941/SQL-LIKE-Operator
– Jens Frandsen
Sep 4 '13 at 18:49
...
Convert columns to string in Pandas
...cated dtype.
object dtype breaks dtype-specific operations like DataFrame.select_dtypes(). There isn’t a clear way to select just text
while excluding non-text but still object-dtype columns.
When reading code, the contents of an object dtype array is less clear than 'string'.
See also the se...