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Using Rails serialize to save hash to database
...
add_column :users, :multi_wrong, :text
end
Then Rails will properly convert it into YAML for you (and perform proper serialization). Strings fields are limited in size and will only hold especially-small values.
share...
SELECT DISTINCT on one column
....WHERE SKU LIKE 'FOO%') a WHERE a.RowNumber = 1
– Andre Nel
Jun 21 '17 at 11:46
This works although it's not a CTE ...
How to escape special characters in building a JSON string?
...ncoding library to use. If you simply use language or library functions to convert things to and from JSON, you'll never even need to know JSON's escaping rules. This is what the misguided question asker here ought to have done.
...
Ruby on Rails. How do I use the Active Record .build method in a :belongs to relationship?
... method missing for your find_by_email and find_by_column_name methods. It converts the method you pass to a string and dissects it and tries to match it with your table's column names.
– bigpotato
Oct 16 '13 at 17:57
...
Super-simple example of C# observer/observable with delegates
...re's an example:
using System;
class Observable
{
public event EventHandler SomethingHappened;
public void DoSomething() =>
SomethingHappened?.Invoke(this, EventArgs.Empty);
}
class Observer
{
public void HandleEvent(object sender, EventArgs args)
{
Console.Wri...
Reverse Range in Swift
...in Objective-C) that migrated to Swift C-style for loops and now had to be converted because C-style for loops are going away. This was simply terrifying, because these loops represented the core of my app's logic, and rewriting everything risked breakage. Thus I wanted a notation that would make th...
Why is the standard session lifetime 24 minutes (1440 seconds)?
...e lifetime was specified in seconds.
I'll bet someone just never bothered converting minutes to seconds. It's probable that person was Sascha Schumann. Once that value was coded into the Zend engine, it became the configuration (php.ini) default as well.
...
Resolve promises one after another (i.e. in sequence)?
... take your work
const urls = ['/url1', '/url2', '/url3', '/url4']
// next convert each item to a function that returns a promise
const funcs = urls.map(url => () => $.ajax(url))
// execute them serially
serial(funcs)
.then(console.log.bind(console))
...
Explain the encapsulated anonymous function syntax
...to observe, because most ways of attempting to get the returned value will convert the function declaration to a function expression. However, eval shows it:
var r = eval("function f(){}");
console.log(r); // undefined
Calling an empty completion record makes no sense. That's why functi...
Slicing of a NumPy 2d array, or how do I extract an mxm submatrix from an nxn array (n>m)?
...ce 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.
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