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When to add what indexes in a table in Rails
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Should I add "index" to all the foreign keys like "xxx_id"?
It would be better, because it accelerates the search in sorting in this column. And Foreign keys are something searched for a lot.
Since Version 5 of rails the index will be created automatically, for more informatio...
GCM with PHP (Google Cloud Messaging)
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This code will send a GCM message to multiple registration IDs via PHP CURL.
// Payload data you want to send to Android device(s)
// (it will be accessible via intent extras)
$data = array('message' => 'Hello World!');
// The recipient registration tokens for this notifica...
Android - Set fragment id
How can I set a Fragment 's Id so that I can use getSupportFragmentManager().findFragmentById(R.id.--) ?
7 Answers
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How do I create a foreign key in SQL Server?
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create table question_bank
(
question_id uniqueidentifier primary key,
question_exam_id uniqueidentifier not null,
question_text varchar(1024) not null,
question_point_value decimal,
constraint fk_questionbank_exams foreign key (question_exam_id) ...
Mysql error 1452 - Cannot add or update a child row: a foreign key constraint fails
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Quite likely your sourcecodes_tags table contains sourcecode_id values that no longer exists in your sourcecodes table. You have to get rid of those first.
Here's a query that can find those IDs:
SELECT DISTINCT sourcecode_id FROM
sourcecodes_tags tags LEFT JOIN sourcecodes sc ON...
How do I change an HTML selected option using JavaScript?
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Change
document.getElementById('personlist').getElementsByTagName('option')[11].selected = 'selected'
to
document.getElementById('personlist').value=Person_ID;
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How do I add a Fragment to an Activity with a programmatically created content view
...han one problem with that code. A fragment cannot be declared that way, inside the same java file as the activity but not as a public inner class. The framework expects the fragment's constructor (with no parameters) to be public and visible. Moving the fragment into the Activity as an inner class, ...
no gravity for scrollview. how to make content inside scrollview as center
I want the content inside the scrollView as center.
7 Answers
7
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Calendar Recurring/Repeating Events - Best Storage Method
...store repeating/recurring event information as efficiently as possibly. I didn't want to have a large number of rows, and I wanted to easily lookup all events that would take place on a specific date.
The method below is great at storing repeating information that occurs at regular intervals, such ...
How to iterate object in JavaScript? [duplicate]
...in the array.
var data = dictionary.data;
for (var i in data)
{
var id = data[i].id;
var name = data[i].name;
}
You can follow similar approach to iterate the image array.
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