大约有 19,000 项符合查询结果（耗时：0.0225秒） [XML]
Get names of all keys in the collection
...p with $addToSet to get distinct keys across the entire collection. (Use $$ROOT for referencing the top level document.)
db.things.aggregate([
{"$project":{"arrayofkeyvalue":{"$objectToArray":"$$ROOT"}}},
{"$unwind":"$arrayofkeyvalue"},
{"$group":{"_id":null,"allkeys":{"$addToSet":"$arrayofkey...
Using “like” wildcard in prepared statement
I am using prepared statements to execute mysql database queries. And I want to implement a search functionality based on a keyword of sorts.
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nginx showing blank PHP pages
...;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root/$fastcgi_script_name;
}
Double-check the /path/to/fastcgi-params, and make sure that it is present and readable by the nginx user.
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SQL Group By with an Order By
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In all versions of MySQL, simply alias the aggregate in the SELECT list, and order by the alias:
SELECT COUNT(id) AS theCount, `Tag` from `images-tags`
GROUP BY `Tag`
ORDER BY theCount DESC
LIMIT 20
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Using Sinatra for larger projects via multiple files
...rb
main.rb
views/
layout.haml
login.haml
main.haml
config.ru
root = ::File.dirname(__FILE__)
require ::File.join( root, 'app' )
run MyApp.new
app.rb
# encoding: utf-8
require 'sinatra'
require 'haml'
class MyApp < Sinatra::Application
enable :sessions
configure :producti...
Difference between scaling horizontally and vertically for databases [closed]
...MongoDB, Google Cloud Spanner .. and a good example of vertical scaling is MySQL - Amazon RDS (The cloud version of MySQL). It provides an easy way to scale vertically by switching from small to bigger machines. This process often involves downtime.
In-Memory Data Grids such as GigaSpaces XAP, Coher...
How do I include a file over 2 directories back?
... those links if you move your file, is:
require_once($_SERVER['DOCUMENT_ROOT'] . 'directory/directory/file');
DOCUMENT_ROOT is a server variable that represents the base directory that your code is located within.
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Laravel Eloquent ORM Transactions
...t ORM is quite nice, though I'm wondering if there is an easy way to setup MySQL transactions using innoDB in the same fashion as PDO, or if I would have to extend the ORM to make this possible?
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Is there a good reason I see VARCHAR(255) used so often (as opposed to another length)?
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@CharlesBretana: By "fake UTF-8" I mean MySQL's "utf8" encoding, which as I mentioned reserves (and is limited to) 3 bytes per character. This isn't a very good version of UTF-8; if you want decent UTF-8 in MySQL, you have to use its "utf8mb4" encoding. But peopl...
MySQL Query - Records between Today and Last 30 Days
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You can also write this in mysql -
SELECT DATE_FORMAT(create_date, '%m/%d/%Y')
FROM mytable
WHERE create_date < DATE_ADD(NOW(), INTERVAL -1 MONTH);
FIXED
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