Ruby on Rails Reference
Installation
Guide: https://gorails.com/setup/osx/10.14-mojave
Mojave bug: 'An error occurred while installing mysql2 (0.5.2)`
bundle config --local build.mysql2 "--with-ldflags=-L/usr/local/opt/openssl/lib --with-cppflags=-I/usr/local/opt/openssl/include"
New project
rails new MyApp -d mysql --skip-coffee --skip-turbolinks
Migrations
Rails-MySQL integer types
:limit MySQL-Type Col Size Max int (signed)
1 TINYINT 1 byte 127 (127)
2 SMALLINT 2 bytes 32,767 (32k)
3 MEDIUMINT 3 bytes 8,388,607 (8m)
nil, 4, 11 INT(11) 4 bytes 2,147,483,647 (2b)
5..8 BIGINT 8 bytes 9,223,372,036,854,775,807 (9bb)
https://ariejan.net/2009/08/20/once-and-for-all-rails-migrations-integer-limit-option/
Rails-MySQL text types
:limit (bytes) MySQL-type Rails-type
1..255 VARCHAR :string
1..255 TINYTEXT :text
256..65535 TEXT :text
65536..16777215 MEDIUMTEXT :text
..4294967295 LONGTEXT :text
To create a CHAR column:
t.column :token, "char(12)"
To have a custom id column:
create_table :posts, :id => false do |t|
t.integer :id, null: false, limit: 4, options: 'PRIMARY KEY' # <-- doesnt do anything
end
Undo
rake db:rollback STEP=1
Emoji and UTF-8
http://blog.arkency.com/2015/05/how-to-store-emoji-in-a-rails-app-with-a-mysql-database/
http://tech.taskrabbit.com/blog/2014/04/24/active-record-mysql-and-emoji/
http://jasonseifer.com/2014/06/20/rails-4-mysql-and-emoji-mysql2error-incorrect-string-value-error
http://metova.com/dev/blog/2015/05/01/add-emoji-support-rails-4-mysql-5-5/
Innodb one file per table
UTF-8 handling
body
.encode('UTF-8', 'binary', invalid: :replace, undef: :replace, replace: '')
.gsub(/joel/, name)
https://robots.thoughtbot.com/fight-back-utf-8-invalid-byte-sequences
You have middleware in your stack that is forcing this string to UTF-8, even when it is not valid UTF-8. The code that is doing this is bugged.
Observe:
s = "a=\xff"
# => "a=\xFF"
s.force_encoding("binary")
# => "a=\xFF"
s.valid_encoding?
# => true
Rack::Utils.parse_nested_query(s)
# => {"a"=>"\xFF"}
s.force_encoding("utf-8")
# => "a=\xFF"
s.valid_encoding?
# => false
Rack::Utils.parse_nested_query(s)
ArgumentError: invalid byte sequence in UTF-8
http://dev.mensfeld.pl/2014/03/rack-argument-error-invalid-byte-sequence-in-utf-8/
DateTime / strftime
Date (Year, Month, Day):
%Y - Year with century (can be negative, 4 digits at least)
-0001, 0000, 1995, 2009, 14292, etc.
%C - year / 100 (round down. 20 in 2009)
%y - year % 100 (00..99)
%m - Month of the year, zero-padded (01..12)
%_m blank-padded ( 1..12)
%-m no-padded (1..12)
%B - The full month name (``January'')
%^B uppercased (``JANUARY'')
%b - The abbreviated month name (``Jan'')
%^b uppercased (``JAN'')
%h - Equivalent to %b
%d - Day of the month, zero-padded (01..31)
%-d no-padded (1..31)
%e - Day of the month, blank-padded ( 1..31)
%j - Day of the year (001..366)
Time (Hour, Minute, Second, Subsecond):
%H - Hour of the day, 24-hour clock, zero-padded (00..23)
%k - Hour of the day, 24-hour clock, blank-padded ( 0..23)
%I - Hour of the day, 12-hour clock, zero-padded (01..12)
%l - Hour of the day, 12-hour clock, blank-padded ( 1..12)
%P - Meridian indicator, lowercase (``am'' or ``pm'')
%p - Meridian indicator, uppercase (``AM'' or ``PM'')
%M - Minute of the hour (00..59)
%S - Second of the minute (00..59)
%L - Millisecond of the second (000..999)
%N - Fractional seconds digits, default is 9 digits (nanosecond)
%3N millisecond (3 digits)
%6N microsecond (6 digits)
%9N nanosecond (9 digits)
%12N picosecond (12 digits)
Time zone:
%z - Time zone as hour and minute offset from UTC (e.g. +0900)
%:z - hour and minute offset from UTC with a colon (e.g. +09:00)
%::z - hour, minute and second offset from UTC (e.g. +09:00:00)
%:::z - hour, minute and second offset from UTC
(e.g. +09, +09:30, +09:30:30)
%Z - Time zone abbreviation name
Weekday:
%A - The full weekday name (``Sunday'')
%^A uppercased (``SUNDAY'')
%a - The abbreviated name (``Sun'')
%^a uppercased (``SUN'')
%u - Day of the week (Monday is 1, 1..7)
%w - Day of the week (Sunday is 0, 0..6)
ISO 8601 week-based year and week number:
The week 1 of YYYY starts with a Monday and includes YYYY-01-04.
The days in the year before the first week are in the last week of
the previous year.
%G - The week-based year
%g - The last 2 digits of the week-based year (00..99)
%V - Week number of the week-based year (01..53)
Week number:
The week 1 of YYYY starts with a Sunday or Monday (according to %U
or %W). The days in the year before the first week are in week 0.
%U - Week number of the year. The week starts with Sunday. (00..53)
%W - Week number of the year. The week starts with Monday. (00..53)
Seconds since the Unix Epoch:
%s - Number of seconds since 1970-01-01 00:00:00 UTC.
%Q - Number of microseconds since 1970-01-01 00:00:00 UTC.
Literal string:
%n - Newline character (\n)
%t - Tab character (\t)
%% - Literal ``%'' character
Combination:
%c - date and time (%a %b %e %T %Y)
%D - Date (%m/%d/%y)
%F - The ISO 8601 date format (%Y-%m-%d)
%v - VMS date (%e-%b-%Y)
%x - Same as %D
%X - Same as %T
%r - 12-hour time (%I:%M:%S %p)
%R - 24-hour time (%H:%M)
%T - 24-hour time (%H:%M:%S)
%+ - date(1) (%a %b %e %H:%M:%S %Z %Y)
Congratulations @gists! You received a personal award!
You can view your badges on your Steem Board and compare to others on the Steem Ranking
Vote for @Steemitboard as a witness to get one more award and increased upvotes!