DEV Community: n350071🇯🇵

changing code by the version of gem

n350071🇯🇵 — Fri, 11 Mar 2022 03:34:45 +0000

I've dived in the devise gem, and found a interesting if statement.

what is `Devise.activerecord51?` ?

It's this.

preload, eager_load, includes, joins

n350071🇯🇵 — Wed, 09 Feb 2022 02:29:08 +0000

Note

This note is for me.

Table

method	prevent N+1	left outer
preload	YES	NO
eager_load	YES	YES
includes	auto	NO
joins	NO	NO
left_joins	NO	YES

CSS fix scroll

n350071🇯🇵 — Thu, 03 Feb 2022 06:48:42 +0000

😃

<div class='sticky-top-content'>
  <div>
    something..
  </div>
<div>

.sticky-top-content{
  position: sticky;
  top: 5rem;
}

Rails where('n > ?', m) without sql

n350071🇯🇵 — Thu, 03 Feb 2022 03:41:15 +0000

😅 SQL Way

User.where('age > ?' age)

😆 ORM Way

User.where(User.arel_table[:age].gt(age))

You can also use these methods.

= (equal) : eq
< (less than) : lt
<= (less than equal) : lteq
> (greater than) : gt
>= (greater than equal) : gteq

Tips

User.where(User.arel_table[:name].matches("%#{name_likely}%"))

💎 Gem Way

I hear that the gem named "Squeel" is very useful for this case.

User.where{age > target_age}

🐳 error: 'Plugin caching_sha2_password could not be loaded' when run 'db:create'

n350071🇯🇵 — Tue, 01 Feb 2022 05:29:59 +0000

🤔 Problem

error: 'Plugin caching_sha2_password could not be loaded'

😆 Solution

change the IDENTIFIED to mysql_native_password

👌Procedure

1.

$ docker cp hoge.sql [cotaier-id]:/hoge.sql

2. Login to Docker

$ docker ps
$ docker exec -it [container-id] /bin/bash

3. Login to MySQL

$ mysql -u root -p

4. check and alter the root user ones.

Assume that the password is 'password'.

mysql> SELECT user, host, plugin FROM mysql.user;
+------------------+-----------+-----------------------+
| user             | host      | plugin                |
+------------------+-----------+-----------------------+
| root             | %         | caching_sha2_password |
| mysql.infoschema | localhost | caching_sha2_password |
| mysql.session    | localhost | caching_sha2_password |
| mysql.sys        | localhost | caching_sha2_password |
| root             | localhost | caching_sha2_password |
+------------------+-----------+-----------------------+
5 rows in set (0.00 sec)

mysql> alter user 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password';
Query OK, 0 rows affected (0.00 sec)

mysql> alter user 'root'@'%' IDENTIFIED WITH mysql_native_password BY 'password';
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT user, host, plugin FROM mysql.user;
+------------------+-----------+-----------------------+
| user             | host      | plugin                |
+------------------+-----------+-----------------------+
| root             | %         | mysql_native_password |
| mysql.infoschema | localhost | caching_sha2_password |
| mysql.session    | localhost | caching_sha2_password |
| mysql.sys        | localhost | caching_sha2_password |
| root             | localhost | mysql_native_password |
+------------------+-----------+-----------------------+
5 rows in set (0.00 sec)

Parent Note

My Docker note

n350071🇯🇵 ・ Oct 29 '19 ・ 1 min read

#docker

When Rails in Docker goes to down...

n350071🇯🇵 — Mon, 01 Nov 2021 05:57:09 +0000

🤔 Situation

Environment
- Rails 6.1
- Rails in Docker
- AWS EC2
Fully works on development mode
Don't work on EC2 with docker compose

🚀 Treatment

Check standard logs.
This command shows standard log.

docker ps

CONTAINER ID ... NAMES
36b68a26fc66 ... xxx_web_1

docker logs xxx_web_1
# it shows standard log

😅 In my case

The name of file and class are different.
The production mode eager loads all file before starting.
That's the why.

! Unable to load application: Zeitwerk::NameError: expected file /null_strategy.rb to define constant Strategies::Jobs::NullStrategy, but didn't

When rails db:migrate error has occurred because I'd tried it several times.

n350071🇯🇵 — Thu, 21 Jan 2021 03:45:10 +0000

😅 Mysql2::Error: Duplicate column name

Because the last db:migrate had been canceled, some columns had been created and not rollbacked.

root@ccf3d04c49ac:/app# bin/rails db:migrate
Caused by:
Mysql2::Error: Duplicate column name 'landlord_agent_type'

🛠 Fix => Dive into MySQL and fix it by SQL

root@ccf3d04c49ac:/app# bin/rails db
Enter password:

MySQL [eshub_development]> show tables;
+-----------------------------+
| Tables_in_eshub_development |
+-----------------------------+
| contracts_rentals           |
+-----------------------------+
18 rows in set (0.004 sec)

MySQL [eshub_development]> desc contracts_rentals;
+-------------------------------+--------------+------+-----+---------+----------------+
| Field                         | Type         | Null | Key | Default | Extra          |
+-------------------------------+--------------+------+-----+---------+----------------+
| id                            | bigint       | NO   | PRI | NULL    | auto_increment |
| landlord_agent_type           | varchar(255) | YES  |     | NULL    |                |
| landlord_agent_id             | bigint       | YES  |     | NULL    |                |
+-------------------------------+--------------+------+-----+---------+----------------+
33 rows in set (0.005 sec)

MySQL [eshub_development]> alter table contracts_rentals drop column landlord_agent_type;
MySQL [eshub_development]> alter table contracts_rentals drop column landlord_agent_id;

MySQL [eshub_development]> show index from contracts_rentals;
+-------------------+------------+----------------------------------------------------------+--------------+---------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
| Table             | Non_unique | Key_name                                                 | Seq_in_index | Column_name   | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | Visible | Expression |
+-------------------+------------+----------------------------------------------------------+--------------+---------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
| contracts_rentals |          0 | PRIMARY                                                  |            1 | id            | A         |          17 |     NULL |   NULL |      | BTREE      |         |               | YES     | NULL       |
+-------------------+------------+----------------------------------------------------------+--------------+---------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
11 rows in set (0.004 sec)

MySQL [eshub_development]> exit
Bye

2ways for making nested form in Rails

n350071🇯🇵 — Wed, 23 Dec 2020 22:35:27 +0000

1. fields_for

Simple way

<%= form_with(model: rental_form, local: true) do |f| %>
  <%= f.fields_for(:terms, rental_form.terms) do |t| %>
  <div class="row my-3">
    <div class="col-11 mx-auto text-center border shadow">
        <h3>Term</h3>
        <div class="row">
          <div class="col-3 border-right">
            Start ~ End
          </div>
          <div class="col">
            <%= t.date_field :start %>
            ~
            <%= t.date_field :end %>
          </div>
        </div>
    </div>
  </div>
  <% end %>
<% end %>

it needs 2 methods

About the terms_attributes method.

It should be as a public method.
It is called from initialize of the ActiveModel, so you need to include ActiveModel

class Contracts::RentalForm < ApplicationForm
  attr_accessor :terms
  def terms_attributes=(attributes)
    self.terms = attributes.map{ |_, term_attributes|
      Contracts::Rentals::Term.new(term_attributes)
    }
  end
end

class ApplicationForm
  include ActiveModel::Model
end

Example of the params

attributes #=> {"0"=>{"id"=>"5", "start"=>"2020-12-23", "end"=>""}, "1"=>{"id"=>"6", "start"=>"2020-12-23", "end"=>""}}

2. manual setting

You don't need to implement the terms_attributes method.

        <% rental_form.terms.each.with_index do |term, index| %>
        <div class="row">
          <div class="col-3 border-right">
            Start ~ End
          </div>
          <div class="col">
            <%= f.date_field "[terms][#{index}][start]" %>
          </div>
        </div>
        <% end %>

`rbenv install -l`. How can I update it?

n350071🇯🇵 — Fri, 30 Oct 2020 23:11:17 +0000

1. if you use the Homebrew

brew update
brew upgrade ruby-build

2. if you use rbenv plugin

cd ~/.rbenv/plugins/ruby-build
git pull origin master
ruby-build --version

Using if condition in yml for rails

n350071🇯🇵 — Wed, 28 Oct 2020 01:09:27 +0000

We can write a condition in a yml for rails like this.

config/setting.yml

  address: '<%= Date.today < Date.new(2020, 12, 1) ? "Tokyo" : "Osaka" %>'

Data transfer with Migration (マイグレーション中のデータ移行)

n350071🇯🇵 — Mon, 26 Oct 2020 00:56:01 +0000

Point

Model.reset_column_information

It makes AR reload the column information.

Example

class ChangeColumnTypeInCompanies < ActiveRecord::Migration[6.0]
  def up
    add_column    :companies, :r_id, :string, comment: 'registration_id', after: :id

    # マイグレーション中にデータ移行するので、直前に足したカラム情報を読み込む
    # https://github.com/rails/rails/blob/v5.1.4/activerecord/lib/active_record/migration.rb#L409-L424
    Company.reset_column_information
    Company.find_each {|company|
      company.update(r_id: company.registration_number&.to_s)
    }
    remove_column :companies, :registration_number
  end

  def down
    add_column    :companies, :registration_number, :integer
    Company.reset_column_information
    Company.find_each {|company|
      company.update(registration_number: company.r_id&.to_s)
    }
    remove_column :companies, :r_id

  end
end

Rails db:migrate show alter SQL

n350071🇯🇵 — Thu, 01 Oct 2020 03:50:42 +0000

ref: https://qiita.com/pekepek/items/2dc9dfc9ed2b7f3b0f0c

1. make a rake task

task log: :environment do
  ActiveRecord::Base.logger = Logger.new(STDOUT)
end

2. run a rake task with the log task

rake log db:migrate