Class: ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter

Inherits:
AbstractAdapter
  • Object
show all
Includes:
MySQL::Quoting, MySQL::SchemaStatements
Defined in:
lib/active_record/connection_adapters/abstract_mysql_adapter.rb

Direct Known Subclasses

Mysql2Adapter

Defined Under Namespace

Classes: MysqlString, StatementPool

Constant Summary collapse

NATIVE_DATABASE_TYPES =
{
  primary_key: "bigint auto_increment PRIMARY KEY",
  string:      { name: "varchar", limit: 255 },
  text:        { name: "text", limit: 65535 },
  integer:     { name: "int", limit: 4 },
  float:       { name: "float", limit: 24 },
  decimal:     { name: "decimal" },
  datetime:    { name: "datetime" },
  timestamp:   { name: "timestamp" },
  time:        { name: "time" },
  date:        { name: "date" },
  binary:      { name: "blob", limit: 65535 },
  boolean:     { name: "tinyint", limit: 1 },
  json:        { name: "json" },
}

Constants inherited from AbstractAdapter

ActiveRecord::ConnectionAdapters::AbstractAdapter::ADAPTER_NAME, ActiveRecord::ConnectionAdapters::AbstractAdapter::SIMPLE_INT

Instance Attribute Summary

Attributes inherited from AbstractAdapter

#lock, #logger, #owner, #pool, #prepared_statements, #schema_cache, #visitor

Attributes included from QueryCache

#query_cache, #query_cache_enabled

Attributes included from DatabaseStatements

#transaction_manager

Instance Method Summary collapse

Methods included from MySQL::SchemaStatements

#create_schema_dumper, #indexes, #internal_string_options_for_primary_key, #remove_column, #update_table_definition

Methods included from MySQL::Quoting

#_type_cast, #quote_column_name, #quote_table_name, #quoted_binary, #quoted_date, #unquoted_false, #unquoted_true

Methods inherited from AbstractAdapter

#active?, #adapter_name, #case_insensitive_comparison, #close, #column_name_for_operation, #column_name_from_arel_node, #disable_extension, #discard!, #disconnect!, #enable_extension, #expire, #extensions, #lease, #migration_context, #migrations_paths, #prefetch_primary_key?, #raw_connection, #reconnect!, #requires_reloading?, #reset!, #seconds_idle, #steal!, #supports_comments?, #supports_comments_in_create?, #supports_ddl_transactions?, #supports_expression_index?, #supports_extensions?, #supports_foreign_tables?, #supports_json?, #supports_multi_insert?, #supports_partial_index?, #supports_savepoints?, #supports_validate_constraints?, type_cast_config_to_boolean, type_cast_config_to_integer, #unprepared_statement, #valid_type?, #verify!

Methods included from Savepoints

#create_savepoint, #current_savepoint_name, #exec_rollback_to_savepoint, #release_savepoint

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

#allowed_index_name_length, #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

#lookup_cast_type_from_column, #quote, #quote_column_name, #quote_default_expression, #quote_string, #quote_table_name, #quote_table_name_for_assignment, #quoted_binary, #quoted_date, #quoted_false, #quoted_time, #quoted_true, #type_cast, #type_cast_from_column, #type_casted_binds, #unquoted_false, #unquoted_true

Methods included from DatabaseStatements

#add_transaction_record, #cacheable_query, #default_sequence_name, #delete, #exec_delete, #exec_insert, #exec_query, #exec_update, #insert, #insert_fixture, #insert_fixtures, #query, #query_value, #query_values, #reset_sequence!, #reset_transaction, #rollback_db_transaction, #rollback_to_savepoint, #sanitize_limit, #select_all, #select_one, #select_rows, #select_value, #select_values, #supports_statement_cache?, #to_sql, #transaction, #transaction_isolation_levels, #transaction_open?, #transaction_state, #update

Methods included from SchemaStatements

#add_column, #add_foreign_key, #add_index_options, #add_reference, #add_timestamps, #assume_migrated_upto_version, #change_table, #column_exists?, #columns, #create_join_table, #create_schema_dumper, #create_table, #data_source_exists?, #data_sources, #drop_join_table, #dump_schema_information, #foreign_key_column_for, #foreign_key_exists?, #foreign_key_options, #index_exists?, #index_name, #index_name_exists?, #indexes, #internal_string_options_for_primary_key, #options_include_default?, #primary_key, #remove_column, #remove_columns, #remove_foreign_key, #remove_index, #remove_reference, #remove_timestamps, #table_alias_for, #table_exists?, #tables, #update_table_definition, #view_exists?, #views

Constructor Details

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

Returns a new instance of AbstractMysqlAdapter.



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 53

def initialize(connection, logger, connection_options, config)
  super(connection, logger, config)

  @statements = StatementPool.new(self.class.type_cast_config_to_integer(config[:statement_limit]))

  if version < "5.1.10"
    raise "Your version of MySQL (#{version_string}) is too old. Active Record supports MySQL >= 5.1.10."
  end
end

Instance Method Details

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

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 379

def add_index(table_name, column_name, options = {}) #:nodoc:
  index_name, index_type, index_columns, _, index_algorithm, index_using, comment = add_index_options(table_name, column_name, options)
  sql = "CREATE #{index_type} INDEX #{quote_column_name(index_name)} #{index_using} ON #{quote_table_name(table_name)} (#{index_columns}) #{index_algorithm}".dup
  execute add_sql_comment!(sql, comment)
end

#add_sql_comment!(sql, comment) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 385

def add_sql_comment!(sql, comment) # :nodoc:
  sql << " COMMENT #{quote(comment)}" if comment.present?
  sql
end

#begin_db_transactionObject



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 199

def begin_db_transaction
  execute "BEGIN"
end

#begin_isolated_db_transaction(isolation) ⇒ Object



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 203

def begin_isolated_db_transaction(isolation)
  execute "SET TRANSACTION ISOLATION LEVEL #{transaction_isolation_levels.fetch(isolation)}"
  begin_db_transaction
end

#bulk_change_table(table_name, operations) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 295

def bulk_change_table(table_name, operations) #:nodoc:
  sqls = operations.flat_map do |command, args|
    table, arguments = args.shift, args
    method = :"#{command}_for_alter"

    if respond_to?(method, true)
      send(method, table, *arguments)
    else
      raise "Unknown method called : #{method}(#{arguments.inspect})"
    end
  end.join(", ")

  execute("ALTER TABLE #{quote_table_name(table_name)} #{sqls}")
end

#case_sensitive_comparison(table, attribute, column, value) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 493

def case_sensitive_comparison(table, attribute, column, value) # :nodoc:
  if column.collation && !column.case_sensitive?
    table[attribute].eq(Arel::Nodes::Bin.new(value))
  else
    super
  end
end

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

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 370

def change_column(table_name, column_name, type, options = {}) #:nodoc:
  execute("ALTER TABLE #{quote_table_name(table_name)} #{change_column_for_alter(table_name, column_name, type, options)}")
end

#change_column_comment(table_name, column_name, comment) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 366

def change_column_comment(table_name, column_name, comment) #:nodoc:
  change_column table_name, column_name, nil, comment: comment
end

#change_column_default(table_name, column_name, default_or_changes) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 353

def change_column_default(table_name, column_name, default_or_changes) #:nodoc:
  default = extract_new_default_value(default_or_changes)
  change_column table_name, column_name, nil, default: default
end

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

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 358

def change_column_null(table_name, column_name, null, default = nil) #:nodoc:
  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, nil, null: null
end

#change_table_comment(table_name, comment) ⇒ Object

:nodoc:



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

def change_table_comment(table_name, comment) #:nodoc:
  comment = "" if comment.nil?
  execute("ALTER TABLE #{quote_table_name(table_name)} COMMENT #{quote(comment)}")
end

#charsetObject

Returns the database character set.



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

def charset
  show_variable "character_set_database"
end

#clear_cache!Object

Clears the prepared statements cache.



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 165

def clear_cache!
  reload_type_map
  @statements.clear
end

#collationObject

Returns the database collation strategy.



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

def collation
  show_variable "collation_database"
end

#columns_for_distinct(columns, orders) ⇒ Object

In MySQL 5.7.5 and up, ONLY_FULL_GROUP_BY affects handling of queries that use DISTINCT and ORDER BY. It requires the ORDER BY columns in the select list for distinct queries, and requires that the ORDER BY include the distinct column. See dev.mysql.com/doc/refman/5.7/en/group-by-handling.html



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 510

def columns_for_distinct(columns, orders) # :nodoc:
  order_columns = orders.reject(&:blank?).map { |s|
    # Convert Arel node to string
    s = s.to_sql unless s.is_a?(String)
    # Remove any ASC/DESC modifiers
    s.gsub(/\s+(?:ASC|DESC)\b/i, "")
  }.reject(&:blank?).map.with_index { |column, i| "#{column} AS alias_#{i}" }

  (order_columns << super).join(", ")
end

#commit_db_transactionObject

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 208

def commit_db_transaction #:nodoc:
  execute "COMMIT"
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/abstract_mysql_adapter.rb', line 250

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

#current_databaseObject



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 266

def current_database
  query_value("SELECT database()", "SCHEMA")
end

#default_index_type?(index) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 525

def default_index_type?(index) # :nodoc:
  index.using == :btree || super
end

#disable_referential_integrityObject

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



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 151

def disable_referential_integrity #:nodoc:
  old = query_value("SELECT @@FOREIGN_KEY_CHECKS")

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

#drop_database(name) ⇒ Object

Drops a MySQL database.

Example:

drop_database('sebastian_development')


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

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

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

Drops a table from the database.

:force

Set to :cascade to drop dependent objects as well. Defaults to false.

:if_exists

Set to true to only drop the table if it exists. Defaults to false.

:temporary

Set to true to drop temporary table. Defaults to false.

Although this command ignores most options and the block if one is given, it can be helpful to provide these in a migration’s change method so it can be reverted. In that case, options and the block will be used by create_table.



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 339

def drop_table(table_name, options = {})
  execute "DROP#{' TEMPORARY' if options[:temporary]} TABLE#{' IF EXISTS' if options[:if_exists]} #{quote_table_name(table_name)}#{' CASCADE' if options[:force] == :cascade}"
end

#each_hash(result) ⇒ Object

The two drivers have slightly different ways of yielding hashes of results, so this method must be implemented to provide a uniform interface.

Raises:

  • (NotImplementedError)


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 139

def each_hash(result) # :nodoc:
  raise NotImplementedError
end

#empty_insert_statement_valueObject



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 228

def empty_insert_statement_value
  "VALUES ()"
end

#emulate_booleansObject

:singleton-method: By default, the Mysql2Adapter will consider all columns of type tinyint(1) as boolean. If you wish to disable this emulation you can add the following line to your application.rb file:

ActiveRecord::ConnectionAdapters::Mysql2Adapter.emulate_booleans = false


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 29

class_attribute :emulate_booleans, default: true

#error_number(exception) ⇒ Object

Must return the MySQL error number from the exception, if the exception has an error number.

Raises:

  • (NotImplementedError)


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

def error_number(exception) # :nodoc:
  raise NotImplementedError
end

#exec_rollback_db_transactionObject

:nodoc:



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

def exec_rollback_db_transaction #:nodoc:
  execute "ROLLBACK"
end

#execute(sql, name = nil) ⇒ Object

Executes the SQL statement in the context of this connection.



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 184

def execute(sql, name = nil)
  log(sql, name) do
    ActiveSupport::Dependencies.interlock.permit_concurrent_loads do
      @connection.query(sql)
    end
  end
end

#execute_and_free(sql, name = nil) {|execute(sql, name)| ... } ⇒ Object

Mysql2Adapter doesn’t have to free a result after using it, but we use this method to write stuff in an abstract way without concerning ourselves about whether it needs to be explicitly freed or not.

Yields:



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 195

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

#explain(arel, binds = []) ⇒ Object

– DATABASE STATEMENTS ====================================== ++



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 174

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

  MySQL::ExplainPrettyPrinter.new.pp(result, elapsed)
end

#foreign_keys(table_name) ⇒ Object

Raises:

  • (ArgumentError)


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 390

def foreign_keys(table_name)
  raise ArgumentError unless table_name.present?

  scope = quoted_scope(table_name)

  fk_info = exec_query(<<-SQL.strip_heredoc, "SCHEMA")
    SELECT fk.referenced_table_name AS 'to_table',
           fk.referenced_column_name AS 'primary_key',
           fk.column_name AS 'column',
           fk.constraint_name AS 'name',
           rc.update_rule AS 'on_update',
           rc.delete_rule AS 'on_delete'
    FROM information_schema.referential_constraints rc
    JOIN information_schema.key_column_usage fk
    USING (constraint_schema, constraint_name)
    WHERE fk.referenced_column_name IS NOT NULL
      AND fk.table_schema = #{scope[:schema]}
      AND fk.table_name = #{scope[:name]}
      AND rc.constraint_schema = #{scope[:schema]}
      AND rc.table_name = #{scope[:name]}
  SQL

  fk_info.map do |row|
    options = {
      column: row["column"],
      name: row["name"],
      primary_key: row["primary_key"]
    }

    options[:on_update] = extract_foreign_key_action(row["on_update"])
    options[:on_delete] = extract_foreign_key_action(row["on_delete"])

    ForeignKeyDefinition.new(table_name, row["to_table"], options)
  end
end

#get_advisory_lock(lock_name, timeout = 0) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 119

def get_advisory_lock(lock_name, timeout = 0) # :nodoc:
  query_value("SELECT GET_LOCK(#{quote(lock_name.to_s)}, #{timeout})") == 1
end

#index_algorithmsObject



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 131

def index_algorithms
  { default: "ALGORITHM = DEFAULT".dup, copy: "ALGORITHM = COPY".dup, inplace: "ALGORITHM = INPLACE".dup }
end

#insert_fixtures_set(fixture_set, tables_to_delete = []) ⇒ Object



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 529

def insert_fixtures_set(fixture_set, tables_to_delete = [])
  with_multi_statements do
    super { discard_remaining_results }
  end
end

#join_to_update(update, select, key) ⇒ 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.



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 219

def join_to_update(update, select, key) # :nodoc:
  if select.limit || select.offset || select.orders.any?
    super
  else
    update.table select.source
    update.wheres = select.constraints
  end
end

#mariadb?Boolean

:nodoc:

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 67

def mariadb? # :nodoc:
  /mariadb/i.match?(full_version)
end

#native_database_typesObject



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 127

def native_database_types
  NATIVE_DATABASE_TYPES
end

#primary_keys(table_name) ⇒ Object

:nodoc:

Raises:

  • (ArgumentError)


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

def primary_keys(table_name) # :nodoc:
  raise ArgumentError unless table_name.present?

  scope = quoted_scope(table_name)

  query_values(<<-SQL.strip_heredoc, "SCHEMA")
    SELECT column_name
    FROM information_schema.key_column_usage
    WHERE constraint_name = 'PRIMARY'
      AND table_schema = #{scope[:schema]}
      AND table_name = #{scope[:name]}
    ORDER BY ordinal_position
  SQL
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 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 236

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

#release_advisory_lock(lock_name) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 123

def release_advisory_lock(lock_name) # :nodoc:
  query_value("SELECT RELEASE_LOCK(#{quote(lock_name.to_s)})") == 1
end

#rename_column(table_name, column_name, new_column_name) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 374

def rename_column(table_name, column_name, new_column_name) #:nodoc:
  execute("ALTER TABLE #{quote_table_name(table_name)} #{rename_column_for_alter(table_name, column_name, new_column_name)}")
  rename_column_indexes(table_name, column_name, new_column_name)
end

#rename_index(table_name, old_name, new_name) ⇒ Object



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 343

def rename_index(table_name, old_name, new_name)
  if supports_rename_index?
    validate_index_length!(table_name, new_name)

    execute "ALTER TABLE #{quote_table_name(table_name)} RENAME INDEX #{quote_table_name(old_name)} TO #{quote_table_name(new_name)}"
  else
    super
  end
end

#rename_table(table_name, new_name) ⇒ Object

Renames a table.

Example:

rename_table('octopuses', 'octopi')


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

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

#show_variable(name) ⇒ Object

SHOW VARIABLES LIKE ‘name’



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 472

def show_variable(name)
  query_value("SELECT @@#{name}", "SCHEMA")
rescue ActiveRecord::StatementInvalid
  nil
end

#strict_mode?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 521

def strict_mode?
  self.class.type_cast_config_to_boolean(@config.fetch(:strict, true))
end

#supports_advisory_locks?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 115

def supports_advisory_locks?
  true
end

#supports_bulk_alter?Boolean

:nodoc:

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 71

def supports_bulk_alter? #:nodoc:
  true
end

#supports_datetime_with_precision?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 99

def supports_datetime_with_precision?
  if mariadb?
    version >= "5.3.0"
  else
    version >= "5.6.4"
  end
end

#supports_explain?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 83

def supports_explain?
  true
end

#supports_foreign_keys?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 91

def supports_foreign_keys?
  true
end

#supports_index_sort_order?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 75

def supports_index_sort_order?
  !mariadb? && version >= "8.0.1"
end

#supports_indexes_in_create?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 87

def supports_indexes_in_create?
  true
end

#supports_transaction_isolation?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 79

def supports_transaction_isolation?
  true
end

#supports_views?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 95

def supports_views?
  true
end

#supports_virtual_columns?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 107

def supports_virtual_columns?
  if mariadb?
    version >= "5.2.0"
  else
    version >= "5.7.5"
  end
end

#table_comment(table_name) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 284

def table_comment(table_name) # :nodoc:
  scope = quoted_scope(table_name)

  query_value(<<-SQL.strip_heredoc, "SCHEMA").presence
    SELECT table_comment
    FROM information_schema.tables
    WHERE table_schema = #{scope[:schema]}
      AND table_name = #{scope[:name]}
  SQL
end

#table_options(table_name) ⇒ Object

:nodoc:



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

def table_options(table_name) # :nodoc:
  table_options = {}

  create_table_info = create_table_info(table_name)

  # strip create_definitions and partition_options
  raw_table_options = create_table_info.sub(/\A.*\n\) /m, "").sub(/\n\/\*!.*\*\/\n\z/m, "").strip

  # strip AUTO_INCREMENT
  raw_table_options.sub!(/(ENGINE=\w+)(?: AUTO_INCREMENT=\d+)/, '\1')

  table_options[:options] = raw_table_options

  # strip COMMENT
  if raw_table_options.sub!(/ COMMENT='.+'/, "")
    table_options[:comment] = table_comment(table_name)
  end

  table_options
end

#truncate(table_name, name = nil) ⇒ Object



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 280

def truncate(table_name, name = nil)
  execute "TRUNCATE TABLE #{quote_table_name(table_name)}", name
end

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

Maps logical Rails types to MySQL-specific data types.



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

def type_to_sql(type, limit: nil, precision: nil, scale: nil, unsigned: nil, **) # :nodoc:
  sql = \
    case type.to_s
    when "integer"
      integer_to_sql(limit)
    when "text"
      text_to_sql(limit)
    when "blob"
      binary_to_sql(limit)
    when "binary"
      if (0..0xfff) === limit
        "varbinary(#{limit})"
      else
        binary_to_sql(limit)
      end
    else
      super
    end

  sql = "#{sql} unsigned" if unsigned && type != :primary_key
  sql
end

#versionObject

:nodoc:



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# File 'lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 63

def version #:nodoc:
  @version ||= Version.new(version_string)
end