ruby-mysql

Description

ruby-mysql is a MySQL client library. It is written entirely in Ruby. Therefore libmysqlclient is not required and no compilation is required during installation.

Installation

gem install ruby-mysql

Synopsis

require 'mysql'

my = Mysql.connect('mysql://username:password@hostname:port/dbname?charset=utf8mb4')
my.query("select col1, col2 from tblname").each do |col1, col2|
  p col1, col2
end
stmt = my.prepare('insert into tblname (col1,col2) values (?,?)')
stmt.execute 123, 'abc'

Major incompatibility with 3.0

Result values are now converted by default

MySQL type	Ruby class
NULL	NilClass
INT	Integer
DECIMAL	BigDecimal
FLOAT, DOUBLE	Float
DATE	Date
DATETIME, TIMESTAMP	Time
TIME	Float (as seconds)
YEAR	Integer
CHAR, VARCHAR	String
BIT	String
TEXT, BLOB, JSON	String

3.0:

pp my.query('select 123,123.45,now(),cast(now() as date)').fetch.map{[_1, _1.class]}
#=> [["123", String],
#    ["123.45", String],
#    ["2022-11-15 00:17:11", String],
#    ["2022-11-15", String]]

4.0:

pp my.query('select 123,123.45,now(),cast(now() as date)').fetch.map{[_1, _1.class]}
#=> [[123, Integer],
#    [0.12345e3, BigDecimal],
#    [2022-11-15 00:17:17 +0900, Time],
#    [#<Date: 2022-11-15 ((2459899j,0s,0n),+0s,2299161j)>, Date]]

To specify cast: false, you get the same behavior as in 3.0.

my.query('select 123,123.45,now(),cast(now() as date)', cast: false).fetch.map{[_1, _1.class]}
#=> [["123", String],
#    ["123.45", String],
#    ["2022-11-15 00:19:18", String],
#    ["2022-11-15", String]]

It can also be specified during Mysql.new and Mysql.connect.

my = Mysql.connect('mysql://user:pass@localhost/', cast: false)

Changing mysql.default_options will affect the behavior of subsequently created instances.

my1 = Mysql.connect('mysql://user:pass@localhost/')
Mysql.default_options[:cast] = false
my2 = Mysql.connect('mysql://user:pass@localhost/')
pp my1.query('select 123,123.45,now(),cast(now() as date)').fetch.map{[_1, _1.class]}
#=> [[123, Integer],
#    [0.12345e3, BigDecimal],
#    [2022-11-15 00:26:09 +0900, Time],
#    [#<Date: 2022-11-15 ((2459899j,0s,0n),+0s,2299161j)>, Date]]
pp my2.query('select 123,123.45,now(),cast(now() as date)').fetch.map{[_1, _1.class]}
#=> [["123", String],
#    ["123.45", String],
#    ["2022-11-15 00:26:09", String],
#    ["2022-11-15", String]]

Mysql::Result#each now always return records from the beginning

3.0:

res = my.query('select 123 union select 456')
res.entries
#=> [["123"], ["456"]]
res.entries
#=> []

4.0:

res = my.query('select 123 union select 456')
res.entries
#=> [[123], [456]]
res.entries
#=> [[123], [456]]

Copyright

Author: TOMITA Masahiro [email protected]
License: MIT