Class: ActiveRecord::ConnectionAdapters::MysqlAdapter

Inherits:
AbstractAdapter show all
Defined in:
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 collapse

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 Attribute Summary

Attributes included from QueryCache

#query_cache, #query_cache_enabled

Instance Method Summary collapse

Methods inherited from AbstractAdapter

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

Methods included from QueryCache

#cache, #clear_query_cache, dirties_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

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, #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) ⇒ MysqlAdapter

Returns a new instance of MysqlAdapter.



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# File '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

#active?Boolean

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

Returns:

  • (Boolean)


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# File '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

#adapter_nameObject

:nodoc:



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

def adapter_name #:nodoc:
  ADAPTER_NAME
end

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



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 466

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 'lib/active_record/connection_adapters/mysql_adapter.rb', line 533

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

:nodoc:



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# File '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

#begin_db_transactionObject

:nodoc:



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

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

#case_sensitive_equality_operatorObject



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 564

def case_sensitive_equality_operator
  "= BINARY"
end

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

:nodoc:



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

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

#change_column_default(table_name, column_name, default) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 473

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

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



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 478

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 'lib/active_record/connection_adapters/mysql_adapter.rb', line 396

def charset
  show_variable 'character_set_database'
end

#collationObject

Returns the database collation strategy.



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

def collation
  show_variable 'collation_database'
end

#columns(table_name, name = nil) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 449

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

#commit_db_transactionObject

:nodoc:



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

def commit_db_transaction #:nodoc:
  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 '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

#create_savepointObject



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

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

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

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 458

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

#current_databaseObject



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

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

#disable_referential_integrityObject

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



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# File '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

#disconnect!Object



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

def disconnect!
  @connection.close rescue nil
end

#drop_database(name) ⇒ Object

:nodoc:



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

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

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



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 427

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

#emulate_booleansObject

:singleton-method: By default, the MysqlAdapter will consider all columns of type tinyint(1) as boolean. If you wish to disable this emulation (which was the default behavior in versions 0.13.1 and earlier) you can add the following line to your application.rb file:

ActiveRecord::ConnectionAdapters::MysqlAdapter.emulate_booleans = false


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

cattr_accessor :emulate_booleans

#execute(sql, name = nil) ⇒ Object

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 '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

#indexes(table_name, name = nil) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 431

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

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

:nodoc:



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# File '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

#limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key) ⇒ Object



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

def limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key)
  where_sql
end

#native_database_typesObject

:nodoc:



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

def native_database_types #:nodoc:
  NATIVE_DATABASE_TYPES
end

#pk_and_sequence_for(table) ⇒ Object

Returns a table’s primary key and belonging sequence.



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 548

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

#primary_key(table) ⇒ Object

Returns just a table’s primary key



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

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 '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

#quote_column_name(name) ⇒ Object

:nodoc:



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

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

#quote_string(string) ⇒ Object

:nodoc:



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

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

#quote_table_name(name) ⇒ Object

:nodoc:



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# File '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

#quoted_falseObject



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

def quoted_false
  QUOTED_FALSE
end

#quoted_trueObject



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

def quoted_true
  QUOTED_TRUE
end

#reconnect!Object



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

def reconnect!
  disconnect!
  connect
end

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

:nodoc:



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

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

#release_savepointObject



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

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

#rename_column(table_name, column_name, new_column_name) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 505

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

#rename_table(table_name, new_name) ⇒ Object



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 462

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

#reset!Object



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# File '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

#rollback_db_transactionObject

:nodoc:



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

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

#rollback_to_savepointObject



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

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

#select_rows(sql, name = nil) ⇒ Object

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



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# File '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

#show_variable(name) ⇒ Object

SHOW VARIABLES LIKE ‘name’



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# File 'lib/active_record/connection_adapters/mysql_adapter.rb', line 542

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 '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

#supports_migrations?Boolean

:nodoc:

Returns:

  • (Boolean)


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

def supports_migrations? #:nodoc:
  true
end

#supports_primary_key?Boolean

:nodoc:

Returns:

  • (Boolean)


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

def supports_primary_key? #:nodoc:
  true
end

#supports_savepoints?Boolean

:nodoc:

Returns:

  • (Boolean)


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

def supports_savepoints? #:nodoc:
  true
end

#table_exists?(name) ⇒ Boolean

Returns:

  • (Boolean)


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

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 'lib/active_record/connection_adapters/mysql_adapter.rb', line 405

def tables(name = nil, database = nil) #:nodoc:
  tables = []
  result = execute(["SHOW TABLES", database].compact.join(' IN '), name)
  result.each { |field| tables << field[0] }
  result.free
  tables
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 'lib/active_record/connection_adapters/mysql_adapter.rb', line 520

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

:nodoc:



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

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