Class: ActiveRecord::ConnectionAdapters::MysqlAdapter

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

Overview

The MySQL adapter will work with both Ruby/MySQL, which is a Ruby-based MySQL adapter that comes bundled with Active Record, and with the faster C-based MySQL/Ruby adapter (available both as a gem and from www.tmtm.org/en/mysql/ruby/).

Options:

  • :host - Defaults to "localhost".

  • :port - Defaults to 3306.

  • :socket - Defaults to "/tmp/mysql.sock".

  • :username - Defaults to "root"

  • :password - Defaults to nothing.

  • :database - The name of the database. No default, must be provided.

  • :encoding - (Optional) Sets the client encoding by executing "SET NAMES <encoding>" after connection.

  • :reconnect - Defaults to false (See MySQL documentation: dev.mysql.com/doc/refman/5.0/en/auto-reconnect.html).

  • :sslca - Necessary to use MySQL with an SSL connection.

  • :sslkey - Necessary to use MySQL with an SSL connection.

  • :sslcert - Necessary to use MySQL with an SSL connection.

  • :sslcapath - Necessary to use MySQL with an SSL connection.

  • :sslcipher - Necessary to use MySQL with an SSL connection.

Constant Summary

ADAPTER_NAME = 
'MySQL'.freeze
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".freeze,
  :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 Method Summary (collapse)

Methods inherited from AbstractAdapter

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

Methods included from ActiveSupport::Callbacks

#callback, #run_callbacks

Methods included from ActiveSupport::Concern

#append_features, extended, #included

Methods inherited from QueryCache

#call

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 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, #table_exists?

Methods included from DatabaseStatements

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

Methods included from Quoting

#quoted_date

Constructor Details

- (MysqlAdapter) initialize(connection, logger, connection_options, config)

A new instance of MysqlAdapter



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

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

Instance Method Details

- (Boolean) active?

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

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 236

def active?
  if @connection.respond_to?(:stat)
    @connection.stat
  else
    @connection.query 'select 1'
  end

  # mysql-ruby doesn't raise an exception when stat fails.
  if @connection.respond_to?(:errno)
    @connection.errno.zero?
  else
    true
  end
rescue Mysql::Error
  false
end

- (Object) adapter_name

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 167

def adapter_name #:nodoc:
  ADAPTER_NAME
end

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



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

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

- (Object) add_column_position!(sql, options) 



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 519

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

- (Object) add_limit_offset!(sql, options)

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 340

def add_limit_offset!(sql, options) #:nodoc:
  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

- (Object) begin_db_transaction

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 310

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

- (Object) case_sensitive_equality_operator 



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 550

def case_sensitive_equality_operator
  "= BINARY"
end

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

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 474

def change_column(table_name, column_name, type, options = {}) #:nodoc:
  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

- (Object) change_column_default(table_name, column_name, default)

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 459

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

- (Object) change_column_null(table_name, column_name, null, default = nil) 



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 464

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

- (Object) charset

Returns the database character set.



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

def charset
  show_variable 'character_set_database'
end

- (Object) collation

Returns the database collation strategy.



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 401

def collation
  show_variable 'collation_database'
end

- (Object) columns(table_name, name = nil)

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 435

def columns(table_name, name = nil)#:nodoc:
  sql = "SHOW FIELDS FROM #{quote_table_name(table_name)}"
  columns = []
  result = execute(sql, :skip_logging)
  result.each { |field| columns << MysqlColumn.new(field[0], field[4], field[1], field[2] == "YES") }
  result.free
  columns
end

- (Object) commit_db_transaction

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 316

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

- (Object) create_database(name, options = {})

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/mysql_adapter.rb', line 379

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

- (Object) create_savepoint 



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 328

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

- (Object) create_table(table_name, options = {})

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 444

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

- (Object) current_database 



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 391

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

- (Object) disable_referential_integrity

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



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 223

def disable_referential_integrity #: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

- (Object) disconnect! 



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 258

def disconnect!
  @connection.close rescue nil
end

- (Object) drop_database(name)

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 387

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

- (Object) drop_table(table_name, options = {}) 



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 413

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

- (Object) execute(sql, name = nil)

Executes an SQL query and returns a MySQL::Result object. Note that you have to free the Result object after you're done using it.



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 285

def execute(sql, name = nil) #:nodoc:
  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

- (Object) indexes(table_name, name = nil)

:nodoc:



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

def indexes(table_name, name = nil)#:nodoc:
  indexes = []
  current_index = nil
  result = execute("SHOW KEYS FROM #{quote_table_name(table_name)}", name)
  result.each do |row|
    if current_index != row[2]
      next if row[2] == "PRIMARY" # skip the primary key
      current_index = row[2]
      indexes << IndexDefinition.new(row[0], row[2], row[1] == "0", [], [])
    end

    indexes.last.columns << row[4]
    indexes.last.lengths << row[7]
  end
  result.free
  indexes
end

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

:nodoc:



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

def insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) #:nodoc:
  super sql, name
  id_value || @connection.insert_id
end

- (Object) limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key) 



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 554

def limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key)
  where_sql
end

- (Object) native_database_types

:nodoc:



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

def native_database_types #:nodoc:
  NATIVE_DATABASE_TYPES
end

- (Object) pk_and_sequence_for(table)

Returns a table's primary key and belonging sequence.



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 534

def pk_and_sequence_for(table) #:nodoc:
  keys = []
  result = execute("describe #{quote_table_name(table)}")
  result.each_hash do |h|
    keys << h["Field"]if h["Key"] == "PRI"
  end
  result.free
  keys.length == 1 ? [keys.first, nil] : nil
end

- (Object) primary_key(table)

Returns just a table's primary key



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 545

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

- (Object) quote(value, column = nil)

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



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 190

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

- (Object) quote_column_name(name)

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 201

def quote_column_name(name) #:nodoc:
  @quoted_column_names[name] ||= "`#{name}`"
end

- (Object) quote_string(string)

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 209

def quote_string(string) #:nodoc:
  @connection.quote(string)
end

- (Object) quote_table_name(name)

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 205

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

- (Object) quoted_false 



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 217

def quoted_false
  QUOTED_FALSE
end

- (Object) quoted_true 



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 213

def quoted_true
  QUOTED_TRUE
end

- (Object) reconnect! 



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 253

def reconnect!
  disconnect!
  connect
end

- (Object) recreate_database(name, options = {})

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 367

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

- (Object) release_savepoint 



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

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

- (Object) rename_column(table_name, column_name, new_column_name)

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 491

def rename_column(table_name, column_name, new_column_name) #:nodoc:
  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

- (Object) rename_table(table_name, new_name) 



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 448

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

- (Object) reset! 



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 262

def reset!
  if @connection.respond_to?(:change_user)
    # See http://bugs.mysql.com/bug.php?id=33540 -- the workaround way to
    # reset the connection is to change the user to the same user.
    @connection.change_user(@config[:username], @config[:password], @config[:database])
    configure_connection
  end
end

- (Object) rollback_db_transaction

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 322

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

- (Object) rollback_to_savepoint 



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 332

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

- (Object) select_rows(sql, name = nil)

DATABASE STATEMENTS ======================================



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 273

def select_rows(sql, name = nil)
  @connection.query_with_result = true
  result = execute(sql, name)
  rows = []
  result.each { |row| rows << row }
  result.free
  @connection.more_results && @connection.next_result    # invoking stored procedures with CLIENT_MULTI_RESULTS requires this to tidy up else connection will be dropped
  rows
end

- (Object) show_variable(name)

SHOW VARIABLES LIKE 'name'



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 528

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

- (Object) structure_dump

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



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

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

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

- (Boolean) supports_migrations?

:nodoc:

Returns:

  • (Boolean) 


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

def supports_migrations? #:nodoc:
  true
end

- (Boolean) supports_primary_key?

:nodoc:

Returns:

  • (Boolean) 


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

def supports_primary_key? #:nodoc:
  true
end

- (Boolean) supports_savepoints?

:nodoc:

Returns:

  • (Boolean) 


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

def supports_savepoints? #:nodoc:
  true
end

- (Object) tables(name = nil)

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 405

def tables(name = nil) #:nodoc:
  tables = []
  result = execute("SHOW TABLES", name)
  result.each { |field| tables << field[0] }
  result.free
  tables
end

- (Object) type_to_sql(type, limit = nil, precision = nil, scale = nil)

Maps logical Rails types to MySQL-specific data types.



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 506

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

- (Object) update_sql(sql, name = nil)

:nodoc:



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# File 'activerecord/lib/active_record/connection_adapters/mysql_adapter.rb', line 305

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