Module: Sequel::MySQL::DatabaseMethods

Included in:
DataObjects::MySQL::DatabaseMethods, JDBC::MySQL::DatabaseMethods, Database
Defined in:
lib/sequel/lib/sequel/adapters/shared/mysql.rb

Overview

Methods shared by Database instances that connect to MySQL, currently supported by the native and JDBC adapters.

Constant Summary collapse

AUTO_INCREMENT =
'AUTO_INCREMENT'.freeze
CAST_TYPES =
{String=>:CHAR, Integer=>:SIGNED, Time=>:DATETIME, DateTime=>:DATETIME, Numeric=>:DECIMAL, BigDecimal=>:DECIMAL, File=>:BINARY}
PRIMARY =
'PRIMARY'.freeze

Instance Method Summary collapse

Instance Method Details

#cast_type_literal(type) ⇒ Object

MySQL's cast rules are restrictive in that you can't just cast to any possible database type.


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# File 'lib/sequel/lib/sequel/adapters/shared/mysql.rb', line 17

def cast_type_literal(type)
  CAST_TYPES[type] || super
end

#database_typeObject

MySQL uses the :mysql database type


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# File 'lib/sequel/lib/sequel/adapters/shared/mysql.rb', line 22

def database_type
  :mysql
end

#indexes(table) ⇒ Object

Return a hash containing index information. Hash keys are index name symbols. Values are subhashes with two keys, :columns and :unique. The value of :columns is an array of symbols of column names. The value of :unique is true or false depending on if the index is unique.

Does not include the primary key index or indexes on partial keys.


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# File 'lib/sequel/lib/sequel/adapters/shared/mysql.rb', line 32

def indexes(table)
  indexes = {}
  remove_indexes = []
  m = output_identifier_meth
  im = input_identifier_meth
  .with_sql("SHOW INDEX FROM ?", SQL::Identifier.new(im.call(table))).each do |r|
    name = r[:Key_name]
    next if name == PRIMARY
    name = m.call(name)
    remove_indexes << name if r[:Sub_part]
    i = indexes[name] ||= {:columns=>[], :unique=>r[:Non_unique] != 1}
    i[:columns] << m.call(r[:Column_name])
  end
  indexes.reject{|k,v| remove_indexes.include?(k)}
end

#server_versionObject

Get version of MySQL server, used for determined capabilities.


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# File 'lib/sequel/lib/sequel/adapters/shared/mysql.rb', line 49

def server_version
  m = /(\d+)\.(\d+)\.(\d+)/.match(get(SQL::Function.new(:version)))
  @server_version ||= (m[1].to_i * 10000) + (m[2].to_i * 100) + m[3].to_i
end

#supports_savepoints?Boolean

MySQL supports savepoints


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# File 'lib/sequel/lib/sequel/adapters/shared/mysql.rb', line 64

def supports_savepoints?
  true
end

#tables(opts = {}) ⇒ Object

Return an array of symbols specifying table names in the current database.

Options:

  • :server - Set the server to use


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# File 'lib/sequel/lib/sequel/adapters/shared/mysql.rb', line 58

def tables(opts={})
  m = output_identifier_meth
  .with_sql('SHOW TABLES').server(opts[:server]).map{|r| m.call(r.values.first)}
end

#use(db_name) ⇒ Object

Changes the database in use by issuing a USE statement. I would be very careful if I used this.


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# File 'lib/sequel/lib/sequel/adapters/shared/mysql.rb', line 70

def use(db_name)
  disconnect
  @opts[:database] = db_name if self << "USE #{db_name}"
  @schemas = {}
  self
end