Class: ActiveRecord::ConnectionAdapters::PostgreSQLAdapter

Inherits:
AbstractAdapter
  • Object
show all
Defined in:
lib/connection_adapters/postgresql_adapter.rb

Instance Method Summary collapse

Instance Method Details

#foreign_key_constraints(table, name = nil) ⇒ Object 



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# File 'lib/connection_adapters/postgresql_adapter.rb', line 11

def foreign_key_constraints(table, name = nil)
  
  
  sql =  "SELECT conname, pg_catalog.pg_get_constraintdef(oid) AS consrc FROM pg_catalog.pg_constraint WHERE contype='f' "
  sql += "AND conrelid = (SELECT oid FROM pg_catalog.pg_class WHERE relname='#{table}')"
  
  result = query(sql, name)
  
  keys = []
  re = /(?i)^FOREIGN KEY \((.+)\) REFERENCES (.+)\((.+)\)(?: ON UPDATE (\w+))?(?: ON DELETE (\w+))?$/
  result.each do |row| 
    # pg_catalog.pg_get_constraintdef returns a string like this:
    # FOREIGN KEY (user_id) REFERENCES users(id) ON UPDATE CASCADE ON DELETE CASCADE          
    if match = re.match(row[1])
      
      keys << ForeignKeyConstraint.new(row[0],
                                       table,
                                       match[1],
                                       match[2],
                                       match[3],
                                       symbolize_foreign_key_constraint_action(match[4]),
                                       symbolize_foreign_key_constraint_action(match[5]))
    end
  end
  
  keys
end

#remove_foreign_key_constraint(table_name, constraint_name) ⇒ Object 



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# File 'lib/connection_adapters/postgresql_adapter.rb', line 39

def remove_foreign_key_constraint(table_name, constraint_name)
  execute "ALTER TABLE #{table_name} DROP CONSTRAINT #{constraint_name}"
end

#supports_fetch_foreign_keys? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/connection_adapters/postgresql_adapter.rb', line 7

def supports_fetch_foreign_keys?
  true
end