Class: PgMeta::Constraint

Inherits:

Node

• Object
• Node
• PgMeta::Constraint

Defined in:

lib/pg_meta/meta.rb

Direct Known Subclasses

CheckConstraint, PrimaryKeyConstraint, ReferentialConstraint, UniqueConstraint

Instance Attribute Summary

• #columns ⇒ Object readonly

  List of columns in the constraint.

Attributes inherited from Node

#name, #parent, #root

Instance Method Summary

• #column ⇒ Object

  Constraint column.

• #initialize(table, name, columns) ⇒ Constraint constructor

  A new instance of Constraint.

• #kind ⇒ Object

  Constraint kind.

• #to_h ⇒ Object

Methods inherited from Node

#dump, #dump_value, #guid, #inspect, #sid, #to_s, #to_yaml, #uid

Constructor Details

#initialize(table, name, columns) ⇒ Constraint

Returns a new instance of Constraint.

# File 'lib/pg_meta/meta.rb', line 437

def initialize(table, name, columns)
  super(table, name)
  @table = table
  @columns = columns
  table.constraints[name] = self
end

Instance Attribute Details

#columns ⇒ Object (readonly)

List of columns in the constraint. Empty for CheckConstraint objects except not null constraints

# File 'lib/pg_meta/meta.rb', line 432

def columns
  @columns
end

Instance Method Details

#column ⇒ Object

Constraint column. Raise an error if the constraint is multi-column

# File 'lib/pg_meta/meta.rb', line 425

def column
  columns.size == 1 or raise "Multicolumn constraint"
  columns.first
end

#kind ⇒ Object

Constraint kind. Either :primary_key, :unique, :check, or :referential

# File 'lib/pg_meta/meta.rb', line 435

def kind() CONSTRAINT_KINDS[self.class] end

#to_h ⇒ Object

# File 'lib/pg_meta/meta.rb', line 444

def to_h() attrs_to_h(:name, :kind, :columns) end