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

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

Constant Summary collapse

ESCAPE_RE = 
/("|\\)/.freeze
ESCAPE_REPLACEMENT = 
'\\\\\1'.freeze
COMMA = 
','.freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#row_types ⇒ Object (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 361

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 364

def self.extended(db)
  # Return right away if row_types has already been set. This
  # makes things not break if a user extends the database with
  # this module more than once (since extended is called every
  # time).
  return if db.row_types

  db.instance_eval do
    @row_types = {}
    @row_schema_types = {}
    extend(@row_type_method_module = Module.new)
  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 379

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

#register_row_type(db_type, 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 400

def register_row_type(db_type, 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{|i| i.to_i}

  # Get column names and oids for each of the members of the composite type.
  res = from(:pg_attribute).
    where(:attrelid=>rel_oid).
    where{attnum > 0}.
    exclude(:attisdropped).
    order(:attnum).
    select_map([:attname, :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|
    if pr = procs[oid]
      pr
    elsif !Sequel::Postgres::STRING_TYPES.include?(oid)
      # It's not a string type, and it's possible a conversion proc for this
      # oid will be added later, so do a runtime check for it.
      lambda{|s| (pr = procs[oid]) ? pr.call(s) : s}
    end
  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)
  @conversion_procs[parser.oid] = parser

  if defined?(PGArray) && PGArray.respond_to?(:register) && array_oid && array_oid > 0
    PGArray.register(db_type, :oid=>array_oid, :converter=>parser, :type_procs=>@conversion_procs, :scalar_typecast=>schema_type_symbol)
  end

  @row_types[db_type] = opts.merge(:parser=>parser)
  @row_schema_types[schema_type_string] = schema_type_symbol 
  @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

#reset_conversion_procs ⇒ Object

When reseting conversion procs, reregister all the row types so that the system tables are introspected again, picking up database changes.



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# File 'lib/sequel/extensions/pg_row.rb', line 477

def reset_conversion_procs
  procs = super

  row_types.each do |db_type, opts|
    register_row_type(db_type, opts)
  end

  procs
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 490

def row_type(db_type, obj)
  (type_hash = @row_types[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

#schema_column_type(db_type) ⇒ Object

Make the column type detection handle registered row types.



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# File 'lib/sequel/extensions/pg_row.rb', line 517

def schema_column_type(db_type)
  if type = @row_schema_types[db_type]
    type
  else
    super
  end
end