大约有 40,000 项符合查询结果（耗时：0.0500秒） [XML]
When to use MongoDB or other document oriented database systems? [closed]
...cal CRUD stuff. Storing what is essentially a huge hash, and being able to select on any of those keys, is what most people use a relational database for. If your DB is 3NF and you don’t do any joins (you’re just selecting a bunch of tables and putting all the objects together, AKA what most peo...
PSQLException: current transaction is aborted, commands ignored until end of transaction block
...t = connection.createStatement();
statement.executeQuery("select * from moobar");
//This SQL is correctly formed, yet it throws the
//'transaction is aborted' SQL Exception, why? Because:
//A. you were in a transaction.
//B. You ran a SQL stateme...
Slicing of a NumPy 2d array, or how do I extract an mxm submatrix from an nxn array (n>m)?
I want to slice a NumPy nxn array. I want to extract an arbitrary selection of m rows and columns of that array (i.e. without any pattern in the numbers of rows/columns), making it a new, mxm array. For this example let us say the array is 4x4 and I want to extract a 2x2 array from it.
...
Random Number Between 2 Double Numbers
...lse
{
// if both negative and positive results are expected we select the sign based on the size of the ranges
double sample = random.NextDouble();
var rate = minAbs / maxAbs;
var absMinValue = Math.Abs(minValue);
bool isNeg = absMinValue <= maxValue ? ...
What's the right way to pass form element state to sibling/parent elements?
...ContextContainer = React.createContext(null);
const initialAppState = {
selected: "Nothing"
};
function App() {
// The app has a state variable and update handler
const [appState, updateAppState] = useState(initialAppState);
return (
<div>
<h1>Passing state between c...
Ruby on Rails: getting the max value from a DB column
...
one more way
Bar.select("Max(bar) as max_bar").first.max_bar
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What does “for” attribute do in HTML tag?
...Chrome and Safari, for example, clicking a label that is associated with a select only puts focus on the select rather than expanding the options.
– Emile Pels
Feb 8 '16 at 13:30
2...
How do I sort an observable collection?
... of the sorted partition from the unsorted. Worst case O(n). Essentially a selection sort (See below for output).
public static void Sort<T>(this ObservableCollection<T> collection)
where T : IComparable<T>, IEquatable<T>
{
List<T> sorted = collectio...
Django rest framework nested self-referential objects
... by the OP here and at the same time support this solution for dynamically selecting fields to be serialized. Yprez's solution causes an infinite recursion or requires additional complications to avoid the recursion and properly select fields.
– Louis
Jul 24 '...
How can I disable ReSharper in Visual Studio and enable it again?
...nd to Ctrl alt A. That might be because Re# has bound the Ctrl W to Extend selection
– Default
Feb 21 '13 at 9:52
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