Class: ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 27

class_attribute :emulate_booleans, default: true

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 27

class_attribute :emulate_booleans, default: true

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 535

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

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 128

def supports_advisory_locks?
  true
end

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

def supports_bulk_alter?
  true
end

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

def supports_check_constraints?
  if mariadb?
    database_version >= "10.2.1"
  else
    database_version >= "8.0.16"
  end
end

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 120

def supports_common_table_expressions?
  if mariadb?
    database_version >= "10.2.1"
  else
    database_version >= "8.0.1"
  end
end

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

def supports_datetime_with_precision?
  mariadb? || database_version >= "5.6.4"
end

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

def supports_explain?
  true
end

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

def supports_expression_index?
  !mariadb? && database_version >= "8.0.13"
end

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

def supports_foreign_keys?
  true
end

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

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

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

def supports_indexes_in_create?
  true
end

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

def supports_insert_on_duplicate_skip?
  true
end

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

def supports_insert_on_duplicate_update?
  true
end

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 116

def supports_optimizer_hints?
  !mariadb? && database_version >= "5.7.7"
end

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

def supports_transaction_isolation?
  true
end

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

def supports_views?
  true
end

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 111

def supports_virtual_columns?
  mariadb? || database_version >= "5.7.5"
end

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 222

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

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 282

def charset
  show_variable "character_set_database"
end

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

def check_constraints(table_name)
  if supports_check_constraints?
    scope = quoted_scope(table_name)

    chk_info = exec_query(<<~SQL, "SCHEMA")
      SELECT cc.constraint_name AS 'name',
            cc.check_clause AS 'expression'
      FROM information_schema.check_constraints cc
      JOIN information_schema.table_constraints tc
      USING (constraint_schema, constraint_name)
      WHERE tc.table_schema = #{scope[:schema]}
        AND tc.table_name = #{scope[:name]}
        AND cc.constraint_schema = #{scope[:schema]}
    SQL

    chk_info.map do |row|
      options = {
        name: row["name"]
      }
      expression = row["expression"]
      expression = expression[1..-2] unless mariadb? # remove parentheses added by mysql
      CheckConstraintDefinition.new(table_name, expression, options)
    end
  else
    raise NotImplementedError
  end
end

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 287

def collation
  show_variable "collation_database"
end

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 257

def create_database(name, options = {})
  if options[:collation]
    execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT COLLATE #{quote_table_name(options[:collation])}"
  elsif options[:charset]
    execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT CHARACTER SET #{quote_table_name(options[:charset])}"
  elsif row_format_dynamic_by_default?
    execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT CHARACTER SET `utf8mb4`"
  else
    raise "Configure a supported :charset and ensure innodb_large_prefix is enabled to support indexes on varchar(255) string columns."
  end
end

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 277

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

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 334

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

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 235

def empty_insert_statement_value(primary_key = nil)
  "VALUES ()"
end

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 200

def execute(sql, name = nil)
  materialize_transactions
  mark_transaction_written_if_write(sql)

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

# File 'activerecord/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, "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

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 152

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

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 148

def native_database_types
  NATIVE_DATABASE_TYPES
end

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

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

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

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

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 312

def rename_table(table_name, new_name)
  schema_cache.clear_data_source_cache!(table_name.to_s)
  schema_cache.clear_data_source_cache!(new_name.to_s)
  execute "RENAME TABLE #{quote_table_name(table_name)} TO #{quote_table_name(new_name)}"
  rename_table_indexes(table_name, new_name)
end

# File 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb', line 484

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