Extracts the value from a PostgreSQL column default definition.
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 124
def self.extract_value_from_default(default)
case default
# Numeric types
when /\A\(?(-?\d+(\.\d*)?\)?)\z/
$1
# Character types
when /\A'(.*)'::(?:character varying|bpchar|text)\z/m
$1
# Character types (8.1 formatting)
when /\AE'(.*)'::(?:character varying|bpchar|text)\z/m
$1.gsub(/\\(\d\d\d)/) { $1.oct.chr }
# Binary data types
when /\A'(.*)'::bytea\z/m
$1
# Date/time types
when /\A'(.+)'::(?:time(?:stamp)? with(?:out)? time zone|date)\z/
$1
when /\A'(.*)'::interval\z/
$1
# Boolean type
when 'true'
true
when 'false'
false
# Geometric types
when /\A'(.*)'::(?:point|line|lseg|box|"?path"?|polygon|circle)\z/
$1
# Network address types
when /\A'(.*)'::(?:cidr|inet|macaddr)\z/
$1
# Bit string types
when /\AB'(.*)'::"?bit(?: varying)?"?\z/
$1
# XML type
when /\A'(.*)'::xml\z/m
$1
# Arrays
when /\A'(.*)'::"?\D+"?\[\]\z/
$1
# Object identifier types
when /\A-?\d+\z/
$1
else
# Anything else is blank, some user type, or some function
# and we can't know the value of that, so return nil.
nil
end
end
