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Cannot change column used in a foreign key constraint
...eign key field and reference must be equal.
This means your foreign key disallows changing the type of your field.
One solution would be this:
LOCK TABLES
favorite_food WRITE,
person WRITE;
ALTER TABLE favorite_food
DROP FOREIGN KEY fk_fav_food_person_id,
MODIFY person_id SMALLIN...
How to send a JSON object using html form data
...l form data then you have to decode it using json_decode. You'll then get all data in an array.
$.ajax({
type: "POST",
url: "serverUrl",
data: formData,
success: function(){},
dataType: "json",
contentType : "application/json"
});
...
Difference between RegisterStartupScript and RegisterClientScriptBlock?
...:
a. When you use RegisterStartupScript, it will render your script after all the elements in the page (right before the form's end tag). This enables the script to call or reference page elements without the possibility of it not finding them in the Page's DOM.
Here is the rendered source of the ...
Grouped LIMIT in PostgreSQL: show the first N rows for each group?
... For those who works with like millions rows and seeks for really performant way to do this - poshest's answer is the way to go. Just dont forget to spice ti up with proper indexing.
– Diligent Key Presser
Jun 20 '19 at 8:46
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What is Dependency Injection and Inversion of Control in Spring Framework?
...ted from our application code to the Spring container; this phenomenon is called IoC.
Dependency Injection can be done by setter injection or constructor injection.
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Why do people write the #!/usr/bin/env python shebang on the first line of a Python script?
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If you have several versions of Python installed, /usr/bin/env will ensure the interpreter used is the first one on your environment's $PATH. The alternative would be to hardcode something like #!/usr/bin/python; that's ok, but less flexible.
In Unix, an executable f...
Show an image preview before upload
...
HTML5 comes with File API spec, which allows you to create applications that let the user interact with files locally; That means you can load files and render them in the browser without actually having to upload the files. Part of the File API is the FileReader...
Can you resolve an angularjs promise before you return it?
...Nizet's Plunkr but refactored to work within the context of what was originally asked (i.e. a function call to service) and actually on site.
Inside the service...
function getSomething(id) {
// There will always be a promise so always declare it.
var deferred = $q.defer();
if (Cache[i...
Is 'float a = 3.0;' a correct statement?
...terals notation in specific scenarios.
For performance reasons:
Specifically, consider:
float foo(float x) { return x * 0.42; }
Here the compiler will emit a conversion (that you will pay at runtime) for each returned value. To avoid it you should declare:
float foo(float x) { return x * 0.42...
Is it smart to replace boost::thread and boost::mutex with c++11 equivalents?
...ried explaining the quality of boost, then gave up after some time :( ). Smaller reason why I would like to do it is that I would like to learn c++11 features, because people will start writing code in it.
So:
...