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What's the difference between NOT EXISTS vs. NOT IN vs. LEFT JOIN WHERE IS NULL?
... using Standard SQL.
An obvious omission is the equivalent using EXCEPT:
SELECT a FROM table1
EXCEPT
SELECT a FROM table2
Note in Oracle you need to use the MINUS operator (arguably a better name):
SELECT a FROM table1
MINUS
SELECT a FROM table2
Speaking of proprietary syntax, there may also ...
MySQL Insert into multiple tables? (Database normalization?)
... 2 and 3:
Will stock the LAST_INSERT_ID() in
a MySQL variable:
INSERT ...
SELECT LAST_INSERT_ID() INTO @mysql_variable_here;
INSERT INTO table2 (@mysql_variable_here, ...);
INSERT INTO table3 (@mysql_variable_here, ...);
Will stock the LAST_INSERT_ID() in a
php variable (or any language that
can c...
Getting current device language in iOS?
... will actually return the current region of the device - not the currently selected language. These are often one and the same. However, if I am in North America and I set my language to Japanese, my region will still be English (United States). In order to retrieve the currently selected language, ...
Can CSS detect the number of children an element has?
...i:first-child:nth-last-child(4) ~ li {
width: 25%;
}
The trick is to select the first child when it's also the nth-from-the-last child. This effectively selects based on the number of siblings.
Credit for this technique goes to André Luís (discovered) & Lea Verou (refined).
Don't you j...
How do I prompt for Yes/No/Cancel input in a Linux shell script?
...";;
esac
done
Another method, pointed out by Steven Huwig, is Bash's select command. Here is the same example using select:
echo "Do you wish to install this program?"
select yn in "Yes" "No"; do
case $yn in
Yes ) make install; break;;
No ) exit;;
esac
done
With sele...
What is the difference between a “function” and a “procedure”?
... a Procedure, whereas in a Function we can't.
In SQL:
A Procedure allows SELECT as well as DML (INSERT, UPDATE, DELETE) statements in it, whereas Function allows only SELECT statement in it.
Procedures can not be utilized in a SELECT statement, whereas Functions can be embedded in a SELECT stateme...
How to remove a project (from the workspace) in PHPStorm?
...el.)
1. Click File > Close project
2. From Recent projects, select project, press the fn(on normal keyboard - key between right Alt and Ctrl, not windows key)+Delete
share
|
im...
foreach with index [duplicate]
...
You can do the following
foreach (var it in someCollection.Select((x, i) => new { Value = x, Index = i }) )
{
if (it.Index > SomeNumber) //
}
This will create an anonymous type value for every entry in the collection. It will have two properties
Value: with the ori...
What is the difference between Views and Materialized Views in Oracle?
... you. The downside of a view is that its performance depends on how good a select statement the view is based on. If the select statement used by the view joins many tables, or uses joins based on non-indexed columns, the view could perform poorly.
Materialized views
They are similar to regular vi...
Reading CSV file and storing values into an array
...
LINQ way:
var lines = File.ReadAllLines("test.txt").Select(a => a.Split(';'));
var csv = from line in lines
select (from piece in line
select piece);
^^Wrong - Edit by Nick
It appears the original answerer was attempting to populate csv with a...