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Difference between Key, Primary Key, Unique Key and Index in MySQL
...trieval. An index is typically created on columns used in JOIN, WHERE, and ORDER BY clauses.
Imagine you have a table called users and you want to search for all the users which have the last name 'Smith'. Without an index, the database would have to go through all the records of the table: this i...
Databinding an enum property to a ComboBox in WPF
...r model - the enumeration type - in the view, in the ItemsSource param. In order to keep the view and the model decoupled I would need to create a copy of the enumeration in the ViewModel and code ViewModel to translate between the two... Which would make the solution not that simple any more. Or is...
Expand a div to fill the remaining width
...
It is important to note, that the order of the children matters. The floating element with fixed width has to be above the other one. Took me too long to figure out, why it didn't worked for me with switched order.
– Riplexus
...
How can I see normal print output created during pytest run?
...the running of that command with a custom setuptools test command that (in order):
Monkey-patches the private _pytest API.
Calls the public pytest.main() function to run the py.test command.
This answer monkey-patches py.test's -s and --capture=no options to capture stderr but not stdout. By de...
Pandas - Get first row value of a given column
.... See below for an explanation of why. Because a subtle difference in
the order of indexing makes a big difference in behavior, it is better to use single indexing assignment:
df.iloc[0, df.columns.get_loc('Btime')] = x
df.iloc[0, df.columns.get_loc('Btime')] = x (recommended):
The recommende...
Is it expensive to use try-catch blocks even if an exception is never thrown?
...erved as though its statements, as written in the source code, executed in order up to some line.
Because in a try block an exception can be thrown (at any line in the try block! Some exceptions are thrown asynchronously, such as by calling stop on a Thread (which is deprecated), and even besides t...
HQL ERROR: Path expected for join
...ct u from UserGroup ug inner join ug.user u
where ug.group_id = :groupId
order by u.lastname
As a named query:
@NamedQuery(
name = "User.findByGroupId",
query =
"SELECT u FROM UserGroup ug " +
"INNER JOIN ug.user u WHERE ug.group_id = :groupId ORDER BY u.lastname"
)
Use paths in t...
How can I create Min stl priority_queue?
...;
}
4. Using custom structure or class you can use priority_queue in any order.
Suppose, we want to sort people in descending order according to their salary and if tie then according to their age.
struct people
{
int age,salary;
};
struct compare{
bool operator()(...
Throw an error in a MySQL trigger
... columns (idUser and idGuest) that must be mutually exclusive in the table orders, but i'm fairly new to triggers and i'm finding difficulties in writing it!Thx.
– Nicola Peluchetti
Mar 12 '11 at 14:44
...
CSS3 background image transition
...ormal" state will be first child your container, or change the nth-child() order)
CSS2 solution http://jsfiddle.net/eD2zL/2/ (differences between are just a few selectors)
Basically, you need to hide "normal" state and show their "hover" when you hover it
and that's it, I hope somebody find it us...