ruby mysql2

1. mysql2连接选项

Mysql2::Client.new(
  :host,
  :username,
  :password,
  :port,
  :database,
  :socket = '/path/to/mysql.sock',
  :flags = REMEMBER_OPTIONS | LONG_PASSWORD | LONG_FLAG | TRANSACTIONS | PROTOCOL_41 | SECURE_CONNECTION | MULTI_STATEMENTS,
  :encoding = 'utf8',
  :read_timeout = seconds,
  :write_timeout = seconds,
  :connect_timeout = seconds,
  :connect_attrs = {:program_name => $PROGRAM_NAME, ...},
  :reconnect = true/false,
  :local_infile = true/false,
  :secure_auth = true/false,
  :ssl_mode = :disabled / :preferred / :required / :verify_ca / :verify_identity,
  :default_file = '/path/to/my.cfg',
  :default_group = 'my.cfg section',
  :init_command => sql
  )

2.使用实例

require 'mysql2'

client = Mysql2::Client.new(
    :host     => '127.0.0.1', # 主机
    :username => 'root',      # 用户名
    :password => '',    # 密码
    :database => 'test',      # 数据库
    :encoding => 'utf8'       # 编码
    )
results = client.query("SELECT VERSION()")
results.each do |row|
  puts row
end
puts results.count #结果集中的条数

这里results的class是Mysql2::Result，这个结果集mixin了Enumerable模块；我们可以通过迭代对其进行访问

支持Prepared statements

statement = @client.prepare("SELECT * FROM users WHERE login_count = ?")
result1 = statement.execute(1)
result2 = statement.execute(2)

statement = @client.prepare("SELECT * FROM users WHERE last_login >= ? AND location LIKE ?")
result = statement.execute(1, "CA")

statement = @client.prepare("SELECT * FROM users WHERE last_login >= ? AND location LIKE ?")
result = statement.execute(1, "CA", :as => :array)