Module: Sequel::Postgres::PGRow::DatabaseMethods

Defined in:
lib/sequel/extensions/pg_row.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#row_typesObject (readonly)

A hash mapping row type keys (usually symbols), to option hashes. At the least, the values will contain the :parser option for the Parser instance that the type will use.


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# File 'lib/sequel/extensions/pg_row.rb', line 368

def row_types
  @row_types
end

Class Method Details

.extended(db) ⇒ Object

Do some setup for the data structures the module uses.


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# File 'lib/sequel/extensions/pg_row.rb', line 371

def self.extended(db)
  db.instance_exec do
    @row_types = {}
    @row_schema_types = {}
    extend(@row_type_method_module = Module.new)
    add_conversion_proc(2249, PGRow::Parser.new(:converter=>PGRow::ArrayRow))
    if respond_to?(:register_array_type)
      register_array_type('record', :oid=>2287, :scalar_oid=>2249)
    end
  end
end

Instance Method Details

#bound_variable_arg(arg, conn) ⇒ Object

Handle ArrayRow and HashRow values in bound variables.


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# File 'lib/sequel/extensions/pg_row.rb', line 384

def bound_variable_arg(arg, conn)
  case arg
  when ArrayRow
    "(#{arg.map{|v| bound_variable_array(v) if v}.join(',')})"
  when HashRow
    arg.check_columns!
    "(#{arg.values_at(*arg.columns).map{|v| bound_variable_array(v) if v}.join(',')})"
  else
    super
  end
end

#freezeObject

Freeze the row types and row schema types to prevent adding new ones.


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# File 'lib/sequel/extensions/pg_row.rb', line 397

def freeze
  @row_types.freeze
  @row_schema_types.freeze
  @row_type_method_module.freeze
  super
end

#register_row_type(db_type, opts = OPTS) ⇒ Object

Register a new row type for the Database instance. db_type should be the type symbol. This parses the PostgreSQL system tables to get information the composite type, and by default has the type return instances of a subclass of HashRow.

The following options are supported:

:converter

Use a custom converter for the parser.

:typecaster

Use a custom typecaster for the parser.


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# File 'lib/sequel/extensions/pg_row.rb', line 413

def register_row_type(db_type, opts=OPTS)
  procs = @conversion_procs
  rel_oid = nil
  array_oid = nil
  parser_opts = {}

  # Try to handle schema-qualified types.
  type_schema, type_name = schema_and_table(db_type)
  schema_type_string = type_name.to_s

  # Get basic oid information for the composite type.
  ds = from(:pg_type).
    select{[pg_type[:oid], :typrelid, :typarray]}.
    where([[:typtype, 'c'], [:typname, type_name.to_s]])
  if type_schema
    ds = ds.join(:pg_namespace, [[:oid, :typnamespace], [:nspname, type_schema.to_s]])
    schema_type_symbol = :"pg_row_#{type_schema}__#{type_name}" 
  else
    schema_type_symbol = :"pg_row_#{type_name}"
  end
  unless row = ds.first
    raise Error, "row type #{db_type.inspect} not found in database"
  end
  # Manually cast to integer using to_i, because adapter may not cast oid type
  # correctly (e.g. swift)
  parser_opts[:oid], rel_oid, array_oid = row.values_at(:oid, :typrelid, :typarray).map(&:to_i)

  # Get column names and oids for each of the members of the composite type.
  res = from(:pg_attribute).
    join(:pg_type, :oid=>:atttypid).
    where(:attrelid=>rel_oid).
    where{attnum > 0}.
    exclude(:attisdropped).
    order(:attnum).
    select_map{[:attname, Sequel.case({0=>:atttypid}, pg_type[:typbasetype], pg_type[:typbasetype]).as(:atttypid)]}
  if res.empty?
    raise Error, "no columns for row type #{db_type.inspect} in database"
  end
  parser_opts[:columns] = res.map{|r| r[0].to_sym}
  parser_opts[:column_oids] = res.map{|r| r[1].to_i}

  # Using the conversion_procs, lookup converters for each member of the composite type
  parser_opts[:column_converters] = parser_opts[:column_oids].map do |oid|
    procs[oid]
  end

  # Setup the converter and typecaster
  parser_opts[:converter] = opts.fetch(:converter){HashRow.subclass(db_type, parser_opts[:columns])}
  parser_opts[:typecaster] = opts.fetch(:typecaster, parser_opts[:converter])

  parser = Parser.new(parser_opts)
  add_conversion_proc(parser.oid, parser)

  if respond_to?(:register_array_type) && array_oid && array_oid > 0
    array_type_name = if type_schema
      "#{type_schema}.#{type_name}"
    else
      type_name
    end
    register_array_type(array_type_name, :oid=>array_oid, :converter=>parser, :scalar_typecast=>schema_type_symbol)
  end

  @row_types[literal(db_type)] = opts.merge(:parser=>parser, :type=>db_type)
  @row_schema_types[schema_type_string] = schema_type_symbol 
  @schema_type_classes[schema_type_symbol] = ROW_TYPE_CLASSES
  @row_type_method_module.class_eval do
    meth = :"typecast_value_#{schema_type_symbol}"
    define_method(meth) do |v|
      row_type(db_type, v)
    end
    private meth
  end

  nil
end

#row_type(db_type, obj) ⇒ Object

Handle typecasting of the given object to the given database type. In general, the given database type should already be registered, but if obj is an array, this will handled unregistered types.


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# File 'lib/sequel/extensions/pg_row.rb', line 492

def row_type(db_type, obj)
  (type_hash = @row_types[literal(db_type)]) &&
    (parser = type_hash[:parser])

  case obj
  when ArrayRow, HashRow
    obj
  when Array
    if parser
      parser.typecast(obj)
    else
      obj = ArrayRow.new(obj)
      obj.db_type = db_type
      obj
    end
  when Hash
    if parser 
      parser.typecast(obj)
    else
      raise InvalidValue, "Database#row_type requires the #{db_type.inspect} type have a registered parser and typecaster when called with a hash"
    end
  else
    raise InvalidValue, "cannot convert #{obj.inspect} to row type #{db_type.inspect}"
  end
end