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Converting an array of objects to ActiveRecord::Relation
...e clause will generate a SQL statement with IN that looks something like:
SELECT .... WHERE `my_models`.id IN (2, 3, 4, 6, ....
Keep in mind that the ordering of the array will be lost - But since your objective is only to run a class method on the collection of these objects, I assume it won't b...
What is sharding and why is it important?
... a DBMS for which the locality is quite restricted (say, a user only fires selects with a 'where username = $my_username') it makes sense to put all the usernames starting with A-M on one server and all from N-Z on the other. By this you get near linear scaling for some queries.
Long story short: S...
【解决】mysql_real_connect: Can\'t connect to local MySQL server throu...
【解决】mysql_real_connect: Can't connect to local MySQL server through socket '/tmp/mysql.sock'cant-connect-to-local-mysql-server-through-socket-tmp-mysql-sockmysql_real_connect: Can& 39;t connect to local MySQL server through socket & 39; tmp mysql sock& 39;解决方法（挨个试）：1、ln...
How do I use a file grep comparison inside a bash if/else statement?
...m grep --help, but also see man grep:
Exit status is 0 if any line was selected, 1 otherwise;
if any error occurs and -q was not given, the exit status is 2.
if grep --quiet MYSQL_ROLE=master /etc/aws/hosts.conf; then
echo exists
else
echo not found
fi
You may want to use a more specif...
1114 (HY000): The table is full
...
@Nadh In Ubuntu 16.04 it's part of /etc/mysql/ and is partly splitted into additional files in /etc/mysql/conf.d
– Martin C.
Jun 17 '17 at 22:01
...
Delete sql rows where IDs do not have a match from another table
...HERE f.id IS NULL
Using NOT EXISTS:
DELETE FROM BLOB
WHERE NOT EXISTS(SELECT NULL
FROM FILES f
WHERE f.id = fileid)
Using NOT IN:
DELETE FROM BLOB
WHERE fileid NOT IN (SELECT f.id
FROM FILES f)
Warning
Whenever possible, per...
jQuery dot in ID selector? [duplicate]
...
Use the escaping rules from the jQuery selectors API as follows:
$('#root\\.SomeCoolThing')
From the docs:
To use any of the meta-characters (such as
!"#$%&'()*+,./:;<=>?@[\]^`{|}~) as a literal part of a name, it must
be escaped with with...
Logstash实践: 分布式系统的日志监控 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...（我还要去维护宇宙和平的好嘛）。
这篇文章讲的就是如何解决分布式系统的日志管理问题。先给大家看看最终的效果：
单个屏幕上所有服务器的日志实时滚动着显示。每条日志开头还标明日志的来源（下图）。
实现这...
Where does Android emulator store SQLite database?
...data > your-package-name > databases > your-database-file.
Then select the file, click on the disket icon in the right corner of the screen to download the .db file. If you want to upload a database file to the emulator you can click on the phone icon(beside disket icon) and choose the fi...
Which ORM should I use for Node.js and MySQL? [closed]
I'm rewriting a project to use Node.js. I'd like to keep using MySQL as the DB (even though I don't mind rewriting the schema).
I'm looking for a simple-to-use, reasonable-performance ORM, which supports caching, many-to-one and many-to-many relations.
From the MySQL ORMs I could find, persistencej...