Class: ActiveRecord::ConnectionAdapters::Mysql2Adapter

Inherits:
AbstractAdapter show all
Defined in:
activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb

Constant Summary collapse

ADAPTER_NAME =
'Mysql2'
PRIMARY =
"PRIMARY"
LOST_CONNECTION_ERROR_MESSAGES =
[
"Server shutdown in progress",
"Broken pipe",
"Lost connection to MySQL server during query",
"MySQL server has gone away" ]
NATIVE_DATABASE_TYPES =
{
  :primary_key => "int(11) DEFAULT NULL auto_increment PRIMARY KEY",
  :string      => { :name => "varchar", :limit => 255 },
  :text        => { :name => "text" },
  :integer     => { :name => "int", :limit => 4 },
  :float       => { :name => "float" },
  :decimal     => { :name => "decimal" },
  :datetime    => { :name => "datetime" },
  :timestamp   => { :name => "datetime" },
  :time        => { :name => "time" },
  :date        => { :name => "date" },
  :binary      => { :name => "blob" },
  :boolean     => { :name => "tinyint", :limit => 1 }
}

Instance Attribute Summary

Attributes inherited from AbstractAdapter

#visitor

Attributes included from QueryCache

#query_cache, #query_cache_enabled

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from AbstractAdapter

#clear_cache!, #current_savepoint_name, #decrement_open_transactions, #increment_open_transactions, #open_transactions, #prefetch_primary_key?, #raw_connection, #supports_bulk_alter?, #supports_count_distinct?, #supports_ddl_transactions?, #transaction_joinable=, #verify!

Methods included from ActiveSupport::Callbacks

#run_callbacks

Methods included from ActiveSupport::Concern

#append_features, extended, #included

Methods included from QueryCache

#cache, #clear_query_cache, dirties_query_cache, #disable_query_cache!, #enable_query_cache!, included, #select_all, #uncached

Methods included from DatabaseLimits

#column_name_length, #columns_per_multicolumn_index, #columns_per_table, #in_clause_length, #index_name_length, #indexes_per_table, #joins_per_query, #sql_query_length, #table_alias_length, #table_name_length

Methods included from Quoting

#quoted_date, #type_cast

Methods included from DatabaseStatements

#add_transaction_record, #default_sequence_name, #delete, #empty_insert_statement_value, #insert, #insert_fixture, #outside_transaction?, #reset_sequence!, #sanitize_limit, #select_all, #select_one, #select_value, #select_values, #supports_statement_cache?, #to_sql, #transaction, #update

Methods included from SchemaStatements

#add_column_options!, #add_index, #add_timestamps, #assume_migrated_upto_version, #change_table, #column_exists?, #distinct, #dump_schema_information, #index_exists?, #index_name, #index_name_exists?, #initialize_schema_migrations_table, #remove_column, #remove_index, #remove_index!, #remove_timestamps, #rename_index, #table_alias_for

Constructor Details

#initialize(connection, logger, connection_options, config) ⇒ Mysql2Adapter

Returns a new instance of Mysql2Adapter



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 125

def initialize(connection, logger, connection_options, config)
  super(connection, logger)
  @connection_options, @config = connection_options, config
  @quoted_column_names, @quoted_table_names = {}, {}
  configure_connection
end

Class Method Details

.visitor_for(pool) ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 132

def self.visitor_for(pool) # :nodoc:
  Arel::Visitors::MySQL.new(pool)
end

Instance Method Details

#active?Boolean

CONNECTION MANAGEMENT ====================================

Returns:

  • (Boolean)


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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 210

def active?
  return false unless @connection
  @connection.ping
end

#adapter_nameObject



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 136

def adapter_name
  ADAPTER_NAME
end

#add_column(table_name, column_name, type, options = {}) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 492

def add_column(table_name, column_name, type, options = {})
  add_column_sql = "ALTER TABLE #{quote_table_name(table_name)} ADD #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
  add_column_options!(add_column_sql, options)
  add_column_position!(add_column_sql, options)
  execute(add_column_sql)
end

#add_column_position!(sql, options) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 559

def add_column_position!(sql, options)
  if options[:first]
    sql << " FIRST"
  elsif options[:after]
    sql << " AFTER #{quote_column_name(options[:after])}"
  end
end

#add_limit_offset!(sql, options) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 354

def add_limit_offset!(sql, options)
  limit, offset = options[:limit], options[:offset]
  if limit && offset
    sql << " LIMIT #{offset.to_i}, #{sanitize_limit(limit)}"
  elsif limit
    sql << " LIMIT #{sanitize_limit(limit)}"
  elsif offset
    sql << " OFFSET #{offset.to_i}"
  end
  sql
end

#begin_db_transactionObject



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 324

def begin_db_transaction
  execute "BEGIN"
rescue Exception
  # Transactions aren't supported
end

#case_sensitive_equality_operatorObject



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 589

def case_sensitive_equality_operator
  "= BINARY"
end

#case_sensitive_modifier(node) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 594

def case_sensitive_modifier(node)
  Arel::Nodes::Bin.new(node)
end

#change_column(table_name, column_name, type, options = {}) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 514

def change_column(table_name, column_name, type, options = {})
  column = column_for(table_name, column_name)

  unless options_include_default?(options)
    options[:default] = column.default
  end

  unless options.has_key?(:null)
    options[:null] = column.null
  end

  change_column_sql = "ALTER TABLE #{quote_table_name(table_name)} CHANGE #{quote_column_name(column_name)} #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
  add_column_options!(change_column_sql, options)
  add_column_position!(change_column_sql, options)
  execute(change_column_sql)
end

#change_column_default(table_name, column_name, default) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 499

def change_column_default(table_name, column_name, default)
  column = column_for(table_name, column_name)
  change_column table_name, column_name, column.sql_type, :default => default
end

#change_column_null(table_name, column_name, null, default = nil) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 504

def change_column_null(table_name, column_name, null, default = nil)
  column = column_for(table_name, column_name)

  unless null || default.nil?
    execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
  end

  change_column table_name, column_name, column.sql_type, :null => null
end

#charsetObject

Returns the database character set.



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 417

def charset
  show_variable 'character_set_database'
end

#collationObject

Returns the database collation strategy.



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 422

def collation
  show_variable 'collation_database'
end

#columns(table_name, name = nil) ⇒ Object

Returns an array of Mysql2Column objects for the table specified by table_name.



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 470

def columns(table_name, name = nil)
  sql = "SHOW FIELDS FROM #{quote_table_name(table_name)}"
  columns = []
  result = execute(sql, 'SCHEMA')
  result.each(:symbolize_keys => true, :as => :hash) { |field|
    columns << Mysql2Column.new(field[:Field], field[:Default], field[:Type], field[:Null] == "YES")
  }
  columns
end

#commit_db_transactionObject



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 330

def commit_db_transaction
  execute "COMMIT"
rescue Exception
  # Transactions aren't supported
end

#create_database(name, options = {}) ⇒ Object

Create a new MySQL database with optional :charset and :collation. Charset defaults to utf8.

Example:

create_database 'charset_test', :charset => 'latin1', :collation => 'latin1_bin'
create_database 'matt_development'
create_database 'matt_development', :charset => :big5


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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 396

def create_database(name, options = {})
  if options[:collation]
    execute "CREATE DATABASE `#{name}` DEFAULT CHARACTER SET `#{options[:charset] || 'utf8'}` COLLATE `#{options[:collation]}`"
  else
    execute "CREATE DATABASE `#{name}` DEFAULT CHARACTER SET `#{options[:charset] || 'utf8'}`"
  end
end

#create_savepointObject



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 342

def create_savepoint
  execute("SAVEPOINT #{current_savepoint_name}")
end

#create_table(table_name, options = {}) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 480

def create_table(table_name, options = {})
  super(table_name, options.reverse_merge(:options => "ENGINE=InnoDB"))
end

#current_databaseObject



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 412

def current_database
  select_value 'SELECT DATABASE() as db'
end

#disable_referential_integrity(&block) ⇒ Object

REFERENTIAL INTEGRITY ====================================



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 197

def disable_referential_integrity(&block) #:nodoc:
  old = select_value("SELECT @@FOREIGN_KEY_CHECKS")

  begin
    update("SET FOREIGN_KEY_CHECKS = 0")
    yield
  ensure
    update("SET FOREIGN_KEY_CHECKS = #{old}")
  end
end

#disconnect!Object

Disconnects from the database if already connected. Otherwise, this method does nothing.



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 227

def disconnect!
  unless @connection.nil?
    @connection.close
    @connection = nil
  end
end

#drop_database(name) ⇒ Object

Drops a MySQL database.

Example:

drop_database('sebastian_development')


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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 408

def drop_database(name) #:nodoc:
  execute "DROP DATABASE IF EXISTS `#{name}`"
end

#drop_table(table_name, options = {}) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 447

def drop_table(table_name, options = {})
  super(table_name, options)
end

#exec_delete(sql, name, binds) ⇒ Object Also known as: exec_update



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 306

def exec_delete(sql, name, binds)
  binds = binds.dup

  # Pretend to support bind parameters
  execute sql.gsub("\0") { quote(*binds.shift.reverse) }, name
  @connection.affected_rows
end

#exec_insert(sql, name, binds) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 299

def exec_insert(sql, name, binds)
  binds = binds.dup

  # Pretend to support bind parameters
  execute sql.gsub("\0") { quote(*binds.shift.reverse) }, name
end

#execute(sql, name = nil) ⇒ Object

Executes the SQL statement in the context of this connection.



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 276

def execute(sql, name = nil)
  # make sure we carry over any changes to ActiveRecord::Base.default_timezone that have been
  # made since we established the connection
  @connection.query_options[:database_timezone] = ActiveRecord::Base.default_timezone
  if name == :skip_logging
    @connection.query(sql)
  else
    log(sql, name) { @connection.query(sql) }
  end
rescue ActiveRecord::StatementInvalid => exception
  if exception.message.split(":").first =~ /Packets out of order/
    raise ActiveRecord::StatementInvalid, "'Packets out of order' error was received from the database. Please update your mysql bindings (gem install mysql) and read http://dev.mysql.com/doc/mysql/en/password-hashing.html for more information.  If you're on Windows, use the Instant Rails installer to get the updated mysql bindings."
  else
    raise
  end
end

#indexes(table_name, name = nil) ⇒ Object

Returns an array of indexes for the given table.



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 452

def indexes(table_name, name = nil)
  indexes = []
  current_index = nil
  result = execute("SHOW KEYS FROM #{quote_table_name(table_name)}", 'SCHEMA')
  result.each(:symbolize_keys => true, :as => :hash) do |row|
    if current_index != row[:Key_name]
      next if row[:Key_name] == PRIMARY # skip the primary key
      current_index = row[:Key_name]
      indexes << Mysql2IndexDefinition.new(row[:Table], row[:Key_name], row[:Non_unique] == 0, [], [])
    end

    indexes.last.columns << row[:Column_name]
    indexes.last.lengths << row[:Sub_part]
  end
  indexes
end

#insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) ⇒ Object Also known as: create



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 293

def insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)
  super
  id_value || @connection.last_id
end

#join_to_update(update, select) ⇒ Object

In the simple case, MySQL allows us to place JOINs directly into the UPDATE query. However, this does not allow for LIMIT, OFFSET and ORDER. To support these, we must use a subquery. However, MySQL is too stupid to create a temporary table for this automatically, so we have to give it some prompting in the form of a subsubquery. Ugh!



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 607

def join_to_update(update, select) #:nodoc:
  if select.limit || select.offset || select.orders.any?
    subsubselect = select.clone
    subsubselect.projections = [update.key]

    subselect = Arel::SelectManager.new(select.engine)
    subselect.project Arel.sql(update.key.name)
    subselect.from subsubselect.as('__active_record_temp')

    update.where update.key.in(subselect)
  else
    update.table select.source
    update.wheres = select.constraints
  end
end

#last_inserted_id(result) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 315

def last_inserted_id(result)
  @connection.last_id
end

#limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 598

def limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key)
  where_sql
end

#native_database_typesObject



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 154

def native_database_types
  NATIVE_DATABASE_TYPES
end

#pk_and_sequence_for(table) ⇒ Object

Returns a table's primary key and belonging sequence.



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 574

def pk_and_sequence_for(table)
  keys = []
  result = execute("DESCRIBE #{quote_table_name(table)}", 'SCHEMA')
  result.each(:symbolize_keys => true, :as => :hash) do |row|
    keys << row[:Field] if row[:Key] == "PRI"
  end
  keys.length == 1 ? [keys.first, nil] : nil
end

#primary_key(table) ⇒ Object

Returns just a table's primary key



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 584

def primary_key(table)
  pk_and_sequence = pk_and_sequence_for(table)
  pk_and_sequence && pk_and_sequence.first
end

#quote(value, column = nil) ⇒ Object

QUOTING ==================================================



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 160

def quote(value, column = nil)
  if value.kind_of?(String) && column && column.type == :binary && column.class.respond_to?(:string_to_binary)
    s = column.class.string_to_binary(value).unpack("H*")[0]
    "x'#{s}'"
  elsif value.kind_of?(BigDecimal)
    value.to_s("F")
  else
    super
  end
end

#quote_column_name(name) ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 171

def quote_column_name(name) #:nodoc:
  @quoted_column_names[name] ||= "`#{name.to_s.gsub('`', '``')}`"
end

#quote_string(string) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 179

def quote_string(string)
  @connection.escape(string)
end

#quote_table_name(name) ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 175

def quote_table_name(name) #:nodoc:
  @quoted_table_names[name] ||= quote_column_name(name).gsub('.', '`.`')
end

#quoted_falseObject



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 187

def quoted_false
  QUOTED_FALSE
end

#quoted_trueObject



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 183

def quoted_true
  QUOTED_TRUE
end

#reconnect!Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 215

def reconnect!
  disconnect!
  connect
end

#recreate_database(name, options = {}) ⇒ Object

Drops the database specified on the name attribute and creates it again using the provided options.



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 384

def recreate_database(name, options = {})
  drop_database(name)
  create_database(name, options)
end

#release_savepointObject



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 350

def release_savepoint
  execute("RELEASE SAVEPOINT #{current_savepoint_name}")
end

#rename_column(table_name, column_name, new_column_name) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 531

def rename_column(table_name, column_name, new_column_name)
  options = {}
  if column = columns(table_name).find { |c| c.name == column_name.to_s }
    options[:default] = column.default
    options[:null] = column.null
  else
    raise ActiveRecordError, "No such column: #{table_name}.#{column_name}"
  end
  current_type = select_one("SHOW COLUMNS FROM #{quote_table_name(table_name)} LIKE '#{column_name}'")["Type"]
  rename_column_sql = "ALTER TABLE #{quote_table_name(table_name)} CHANGE #{quote_column_name(column_name)} #{quote_column_name(new_column_name)} #{current_type}"
  add_column_options!(rename_column_sql, options)
  execute(rename_column_sql)
end

#rename_table(table_name, new_name) ⇒ Object

Renames a table.

Example:

rename_table('octopuses', 'octopi')


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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 488

def rename_table(table_name, new_name)
  execute "RENAME TABLE #{quote_table_name(table_name)} TO #{quote_table_name(new_name)}"
end

#requires_reloading?Boolean

this is set to true in 2.3, but we don't want it to be

Returns:

  • (Boolean)


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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 221

def requires_reloading?
  false
end

#reset!Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 234

def reset!
  disconnect!
  connect
end

#rollback_db_transactionObject



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 336

def rollback_db_transaction
  execute "ROLLBACK"
rescue Exception
  # Transactions aren't supported
end

#rollback_to_savepointObject



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 346

def rollback_to_savepoint
  execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}")
end

#select_rows(sql, name = nil) ⇒ Object

Returns an array of arrays containing the field values. Order is the same as that returned by columns.



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 271

def select_rows(sql, name = nil)
  execute(sql, name).to_a
end

#show_variable(name) ⇒ Object

SHOW VARIABLES LIKE 'name'.



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 568

def show_variable(name)
  variables = select_all("SHOW VARIABLES LIKE '#{name}'")
  variables.first['Value'] unless variables.empty?
end

#structure_dumpObject

SCHEMA STATEMENTS ========================================



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 369

def structure_dump
  if supports_views?
    sql = "SHOW FULL TABLES WHERE Table_type = 'BASE TABLE'"
  else
    sql = "SHOW TABLES"
  end

  select_all(sql).inject("") do |structure, table|
    table.delete('Table_type')
    structure += select_one("SHOW CREATE TABLE #{quote_table_name(table.to_a.first.last)}")["Create Table"] + ";\n\n"
  end
end

#substitute_at(column, index) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 191

def substitute_at(column, index)
  Arel.sql "\0"
end

#supports_migrations?Boolean

Returns true, since this connection adapter supports migrations.

Returns:

  • (Boolean)


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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 141

def supports_migrations?
  true
end

#supports_primary_key?Boolean

Returns:

  • (Boolean)


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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 145

def supports_primary_key?
  true
end

#supports_savepoints?Boolean

Returns true, since this connection adapter supports savepoints.

Returns:

  • (Boolean)


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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 150

def supports_savepoints?
  true
end

#table_exists?(name) ⇒ Boolean

Returns:

  • (Boolean)


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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 433

def table_exists?(name)
  return true if super

  name          = name.to_s
  schema, table = name.split('.', 2)

  unless table # A table was provided without a schema
    table  = schema
    schema = nil
  end

  tables(nil, schema).include? table
end

#tables(name = nil, database = nil) ⇒ Object

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 426

def tables(name = nil, database = nil) #:nodoc:
  sql = ["SHOW TABLES", database].compact.join(' IN ')
  execute(sql, 'SCHEMA').collect do |field|
    field.first
  end
end

#type_to_sql(type, limit = nil, precision = nil, scale = nil) ⇒ Object

Maps logical Rails types to MySQL-specific data types.



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 546

def type_to_sql(type, limit = nil, precision = nil, scale = nil)
  return super unless type.to_s == 'integer'

  case limit
  when 1; 'tinyint'
  when 2; 'smallint'
  when 3; 'mediumint'
  when nil, 4, 11; 'int(11)'  # compatibility with MySQL default
  when 5..8; 'bigint'
  else raise(ActiveRecordError, "No integer type has byte size #{limit}")
  end
end

#update_sql(sql, name = nil) ⇒ Object



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# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 319

def update_sql(sql, name = nil)
  super
  @connection.affected_rows
end