Class: ActiveRecord::ConnectionAdapters::Mysql2Adapter

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain: self, AbstractMysqlAdapter, AbstractAdapter, ::ActiveSupport::DescendantsTracker
Instance Chain: self, AbstractMysqlAdapter, AbstractAdapter, ColumnDumper, MonitorMixin, ::ActiveSupport::Callbacks, ::ActiveRecord::QueryCache, DatabaseLimits, Quoting, DatabaseStatements, SchemaStatements
Inherits:	ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter ::Object ActiveRecord::ConnectionAdapters::AbstractAdapter ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter ActiveRecord::ConnectionAdapters::Mysql2Adapter
Defined in:	activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb

Constant Summary

ADAPTER_NAME =
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 32
```
'Mysql2'.freeze
```
MAX_INDEX_LENGTH_FOR_UTF8MB4 =
# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 40
```
191
```

Class Attribute Summary

AbstractMysqlAdapter - Inherited

.emulate_booleans, .emulate_booleans?

Class Method Summary

.new(connection, logger, connection_options, config) ⇒ Mysql2Adapter constructor

AbstractMysqlAdapter - Inherited

.new	FIXME: Make the first parameter more similar for the two adapters.

AbstractAdapter - Inherited

.type_cast_config_to_boolean, .type_cast_config_to_integer

::ActiveSupport::DescendantsTracker - Inherited

clear, descendants, direct_descendants,
store_inherited	This is the only method that is not thread safe, but is only ever called during the eager loading phase.

Instance Attribute Summary

#active? ⇒ Boolean readonly
#supports_explain? ⇒ Boolean readonly

AbstractMysqlAdapter - Inherited

#emulate_booleans, #emulate_booleans?, #strict_mode?, #supports_datetime_with_precision?, #supports_foreign_keys?,
#supports_index_sort_order?	Technically MySQL allows to create indexes with the sort order syntax but at the moment (5.5) it doesn't yet implement them.
#supports_indexes_in_create?,
#supports_migrations?	Returns true, since this connection adapter supports migrations.
#supports_primary_key?,
#supports_transaction_isolation?	MySQL 4 technically support transaction isolation, but it is affected by a bug where the transaction level gets persisted for the whole session:
#supports_views?

AbstractAdapter - Inherited

#active?	Checks whether the connection to the database is still active.
#in_use?	Alias for AbstractAdapter#owner.
#logger, #owner, #pool, #prepared_statements,
#requires_reloading?	Returns true if its required to reload the connection between requests for development mode.
#schema_cache, #schema_cache=, #supports_bulk_alter?,
#supports_ddl_transactions?	Does this adapter support DDL rollbacks in transactions? That is, would CREATE TABLE or ALTER TABLE get rolled back by a transaction?
#supports_explain?	Does this adapter support explain?
#supports_extensions?	Does this adapter support database extensions?
#supports_foreign_keys?	Does this adapter support creating foreign key constraints?
#supports_index_sort_order?	Does this adapter support index sort order?
#supports_indexes_in_create?	Does this adapter support creating indexes in the same statement as creating the table?
#supports_migrations?	Does this adapter support migrations?
#supports_partial_index?	Does this adapter support partial indices?
#supports_primary_key?	Can this adapter determine the primary key for tables not attached to an Active Record class, such as join tables?
#supports_savepoints?	Does this adapter support savepoints?
#supports_transaction_isolation?	Does this adapter support setting the isolation level for a transaction?
#supports_views?	Does this adapter support views?
#visitor

DatabaseStatements - Included

#begin_transaction, #commit_transaction, #current_transaction, #open_transactions, #rollback_transaction,
#supports_statement_cache?	Returns `true` when the connection adapter supports prepared statement caching, otherwise returns `false`
#transaction_open?, #within_new_transaction

Instance Method Summary

#create(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)

Alias for #insert_sql.
#disconnect!

Disconnects from the database if already connected.
#error_number(exception)
#exec_delete(sql, name, binds) (also: #exec_update)
#exec_insert(sql, name, binds, pk = nil, sequence_name = nil)
#exec_query(sql, name = 'SQL', binds = []) (also: #exec_without_stmt)
#exec_update(sql, name, binds)

Alias for #exec_delete.
#exec_without_stmt(sql, name = 'SQL', binds = [])

Alias for #exec_query.
#execute(sql, name = nil)

Executes the SQL statement in the context of this connection.
#explain(arel, binds = [])
#initialize_schema_migrations_table
#insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) (also: #create)
#last_inserted_id(result)
#quote_string(string)
#reconnect! (also: #reset!)
#reset!

Alias for #reconnect!.
#select_rows(sql, name = nil, binds = [])

Returns an array of arrays containing the field values.

AbstractMysqlAdapter - Inherited

#begin_db_transaction, #begin_isolated_db_transaction, #case_insensitive_comparison, #case_sensitive_comparison, #case_sensitive_modifier, #change_column_null,
#charset	Returns the database character set.
#clear_cache!,
#collation	Returns the database collation strategy.
#create_database	Create a new MySQL database with optional `:charset` and `:collation`.
#current_database,
#data_source_exists?	Alias for AbstractMysqlAdapter#table_exists?.
#data_sources	Alias for AbstractMysqlAdapter#tables.
#drop_table, #empty_insert_statement_value,
#execute	Executes the SQL statement in the context of this connection.
#foreign_keys, #index_algorithms, #native_database_types,
#pk_and_sequence_for	Returns a table's primary key and belonging sequence.
#primary_key	Returns just a table's primary key.
#quoted_date, #quoted_false, #quoted_true,
#recreate_database	Drops the database specified on the `name` attribute and creates it again using the provided `options`.
#rename_index,
#rename_table	Renames a table.
#schema_creation,
#show_variable	SHOW VARIABLES LIKE 'name'.
#table_exists?, #truncate,
#type_to_sql	Maps logical ::Rails types to MySQL-specific data types.
#unquoted_false, #unquoted_true, #valid_type?

AbstractAdapter - Inherited

#adapter_name	Returns the human-readable name of the adapter.
#case_insensitive_comparison, #case_sensitive_comparison, #case_sensitive_modifier,
#clear_cache!	Clear any caching the database adapter may be doing, for example clearing the prepared statement cache.
#close	Check the connection back in to the connection pool.
#collector, #create_savepoint, #current_savepoint_name,
#disable_extension	This is meant to be implemented by the adapters that support extensions.
#disable_referential_integrity	Override to turn off referential integrity while executing `&block`.
#disconnect!	Disconnects from the database if already connected.
#enable_extension	This is meant to be implemented by the adapters that support extensions.
#expire,
#extensions	A list of extensions, to be filled in by adapters that support them.
#index_algorithms	A list of index algorithms, to be filled by adapters that support them.
#lease, #new_column,
#prefetch_primary_key?	Should primary key values be selected from their corresponding sequence before the insert statement? If true, next_sequence_value is called before each insert to set the record's primary key.
#raw_connection	Provides access to the underlying database driver for this adapter.
#reconnect!	Disconnects from the database if already connected, and establishes a new connection with the database.
#release_savepoint,
#reset!	Reset the state of this connection, directing the DBMS to clear transactions and other connection-related server-side state.
#schema_creation,
#substitute_at	Returns a bind substitution value given a bind `column` NOTE: The column param is currently being used by the sqlserver-adapter.
#unprepared_statement, #valid_type?,
#verify!	Checks whether the connection to the database is still active (i.e. not stale).

ColumnDumper - Included

#column_spec,
#migration_keys	Lists the valid migration options.
#prepare_column_options	This can be overridden on a Adapter level basis to support other extended datatypes (Example: Adding an array option in the PostgreSQLAdapter).

::ActiveSupport::Callbacks - Included

#run_callbacks

Runs the callbacks for the given event.

::ActiveRecord::QueryCache - Included

#call

DatabaseLimits - Included

#allowed_index_name_length	Returns the maximum allowed length for an index name.
#column_name_length	Returns the maximum length of a column name.
#columns_per_multicolumn_index	Returns the maximum number of columns in a multicolumn index.
#columns_per_table	Returns the maximum number of columns per table.
#in_clause_length	Returns the maximum number of elements in an IN (x,y,z) clause.
#index_name_length	Returns the maximum length of an index name.
#indexes_per_table	Returns the maximum number of indexes per table.
#joins_per_query	Returns maximum number of joins in a single query.
#sql_query_length	Returns the maximum length of an SQL query.
#table_alias_length	Returns the maximum length of a table alias.
#table_name_length	Returns the maximum length of a table name.

Quoting - Included

#quote	Quotes the column value to help prevent SQL injection attacks.
#quote_column_name	Quotes the column name.
#quote_string	Quotes a string, escaping any ' (single quote) and \ (backslash) characters.
#quote_table_name	Quotes the table name.
#quote_table_name_for_assignment	Override to return the quoted table name for assignment.
#quoted_date, #quoted_false, #quoted_true,
#type_cast	Cast a `value` to a type that the database understands.
#unquoted_false, #unquoted_true

DatabaseStatements - Included

#add_transaction_record	Register a record with the current transaction so that its after_commit and after_rollback callbacks can be called.
#begin_db_transaction	Begins the transaction (and turns off auto-committing).
#begin_isolated_db_transaction	Begins the transaction with the isolation level set.
#commit_db_transaction	Commits the transaction (and turns on auto-committing).
#default_sequence_name,
#delete	Executes the delete statement and returns the number of rows affected.
#empty_insert_statement_value,
#exec_delete	Executes delete `sql` statement in the context of this connection using `binds` as the bind substitutes.
#exec_insert	Executes insert `sql` statement in the context of this connection using `binds` as the bind substitutes.
#exec_query	Executes `sql` statement in the context of this connection using `binds` as the bind substitutes.
#exec_update	Executes update `sql` statement in the context of this connection using `binds` as the bind substitutes.
#execute	Executes the SQL statement in the context of this connection.
#initialize,
#insert	Returns the last auto-generated ID from the affected table.
#insert_fixture	Inserts the given fixture into the table.
#reset_sequence!	Set the sequence to the max value of the table's column.
#rollback_db_transaction	Rolls back the transaction (and turns on auto-committing).
#rollback_to_savepoint,
#sanitize_limit	Sanitizes the given LIMIT parameter in order to prevent SQL injection.
#select_all	Returns an ::ActiveRecord::Result instance.
#select_one	Returns a record hash with the column names as keys and column values as values.
#select_rows	Returns an array of arrays containing the field values.
#select_value	Returns a single value from a record.
#select_values	Returns an array of the values of the first column in a select:
#to_sql	Converts an arel AST to SQL.
#transaction	Runs the given block in a database transaction, and returns the result of the block.
#transaction_isolation_levels, #transaction_state,
#truncate	Executes the truncate statement.
#update	Executes the update statement and returns the number of rows affected.

SchemaStatements - Included

#add_belongs_to	Alias for SchemaStatements#add_reference.
#add_column	Adds a new column to the named table.
#add_foreign_key	Adds a new foreign key.
#add_index	Adds a new index to the table.
#add_reference	Adds a reference.
#add_timestamps	Adds timestamps (`created_at` and `updated_at`) columns to `table_name`.
#assume_migrated_upto_version,
#change_column	Changes the column's definition according to the new options.
#change_column_default	Sets a new default value for a column:
#change_column_null	Sets or removes a `NOT NULL` constraint on a column.
#change_table	A block for changing columns in `table`.
#column_exists?	Checks to see if a column exists in a given table.
#columns	Returns an array of Column objects for the table specified by `table_name`.
#create_join_table	Creates a new join table with the name created using the lexical order of the first two arguments.
#create_table	Creates a new table with the name `table_name`.
#data_source_exists?	Checks to see if the data source `name` exists on the database.
#data_sources	Returns the relation names useable to back Active Record models.
#drop_join_table	Drops the join table specified by the given arguments.
#drop_table	Drops a table from the database.
#foreign_keys	Returns an array of foreign keys for the given table.
#index_exists?	Checks to see if an index exists on a table for a given index definition.
#index_name_exists?	Verifies the existence of an index with a given name.
#initialize_schema_migrations_table	Should not be called normally, but this operation is non-destructive.
#native_database_types	Returns a hash of mappings from the abstract data types to the native database types.
#remove_belongs_to	Alias for SchemaStatements#remove_reference.
#remove_column	Removes the column from the table definition.
#remove_columns	Removes the given columns from the table definition.
#remove_foreign_key	Removes the given foreign key from the table.
#remove_index	Removes the given index from the table.
#remove_reference	Removes the reference(s).
#remove_timestamps	Removes the timestamp columns (`created_at` and `updated_at`) from the table definition.
#rename_column	Renames a column.
#rename_index	Renames an index.
#rename_table	Renames a table.
#table_alias_for	Truncates a table alias according to the limits of the current adapter.
#table_exists?	Checks to see if the table `table_name` exists on the database.

Constructor Details

.new(connection, logger, connection_options, config) ⇒ `Mysql2Adapter`

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 34


def initialize(connection, logger, connection_options, config)
  super
  @prepared_statements = false
  configure_connection
end

Instance Attribute Details

#active? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 81


def active?
  @connection.ping
end

#supports_explain? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 49


def supports_explain?
  true
end

Instance Method Details

#create(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)

Alias for #insert_sql.

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 231


alias :create :insert_sql

#disconnect!

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

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 94


def disconnect!
  super
  @connection.close
end

#error_number(exception)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 65


def error_number(exception)
  exception.error_number if exception.respond_to?(:error_number)
end

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

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 237


def exec_delete(sql, name, binds)
  execute to_sql(sql, binds), name
  @connection.affected_rows
end

#exec_insert(sql, name, binds, pk = nil, sequence_name = nil)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 233


def exec_insert(sql, name, binds, pk = nil, sequence_name = nil)
  execute to_sql(sql, binds), name
end

#exec_query(sql, name = 'SQL', binds = []) Also known as: #exec_without_stmt

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 220


def exec_query(sql, name = 'SQL', binds = [])
  result = execute(sql, name)
  ActiveRecord::Result.new(result.fields, result.to_a)
end

#exec_update(sql, name, binds)

Alias for #exec_delete.

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 241


alias :exec_update :exec_delete

#exec_without_stmt(sql, name = 'SQL', binds = [])

Alias for #exec_query.

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 225


alias exec_without_stmt exec_query

#execute(sql, name = nil)

Executes the SQL statement in the context of this connection.

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 212


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

  super
end

#explain(arel, binds = [])

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 103


def explain(arel, binds = [])
  sql     = "EXPLAIN #{to_sql(arel, binds.dup)}"
  start   = Time.now
  result  = exec_query(sql, 'EXPLAIN', binds)
  elapsed = Time.now - start

  ExplainPrettyPrinter.new.pp(result, elapsed)
end

#initialize_schema_migrations_table

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 41


def initialize_schema_migrations_table
  if charset == 'utf8mb4'
    ActiveRecord::SchemaMigration.create_table(MAX_INDEX_LENGTH_FOR_UTF8MB4)
  else
    ActiveRecord::SchemaMigration.create_table
  end
end

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

[ GitHub ]

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


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

#last_inserted_id(result)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 243


def last_inserted_id(result)
  @connection.last_id
end

#quote_string(string)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 73


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

#reconnect! Also known as: #reset!

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 85


def reconnect!
  super
  disconnect!
  connect
end

#reset!

Alias for #reconnect!.

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 90


alias :reset! :reconnect!

#select_rows(sql, name = nil, binds = [])

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

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb', line 207


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

Class: ActiveRecord::ConnectionAdapters::Mysql2Adapter

Constant Summary

::ActiveSupport::Callbacks - Included

AbstractAdapter - Inherited

AbstractMysqlAdapter - Inherited

Class Attribute Summary

AbstractMysqlAdapter - Inherited

Class Method Summary

AbstractMysqlAdapter - Inherited

AbstractAdapter - Inherited

::ActiveSupport::DescendantsTracker - Inherited

Instance Attribute Summary

AbstractMysqlAdapter - Inherited

AbstractAdapter - Inherited

DatabaseStatements - Included

Instance Method Summary

AbstractMysqlAdapter - Inherited

AbstractAdapter - Inherited

ColumnDumper - Included

::ActiveSupport::Callbacks - Included

::ActiveRecord::QueryCache - Included

DatabaseLimits - Included

Quoting - Included

DatabaseStatements - Included

SchemaStatements - Included

Constructor Details

.new(connection, logger, connection_options, config) ⇒ Mysql2Adapter

Instance Attribute Details

#active? ⇒ Boolean (readonly)

#supports_explain? ⇒ Boolean (readonly)

Instance Method Details

#create(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)

#disconnect!

#error_number(exception)

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

#exec_insert(sql, name, binds, pk = nil, sequence_name = nil)

#exec_query(sql, name = 'SQL', binds = []) Also known as: #exec_without_stmt

#exec_update(sql, name, binds)

#exec_without_stmt(sql, name = 'SQL', binds = [])

#execute(sql, name = nil)

#explain(arel, binds = [])

#initialize_schema_migrations_table

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

#last_inserted_id(result)

#quote_string(string)

#reconnect! Also known as: #reset!

#reset!

#select_rows(sql, name = nil, binds = [])

.new(connection, logger, connection_options, config) ⇒ `Mysql2Adapter`

#active? ⇒ `Boolean` (readonly)

#supports_explain? ⇒ `Boolean` (readonly)