some note 2010/7/12 Pavel Stehule <pavel.steh...@gmail.com>: > 2010/7/12 Itagaki Takahiro <itagaki.takah...@gmail.com>: >> https://commitfest.postgresql.org/action/patch_view?id=300 >> >> Why did you add to_string() and to_array() functions though we already >> have string_to_array() and array_to_string() functions? I prefer adding >> three arguments version of string_to_array() instead of to_array(). >> Please notice me if you think to_string() and to_array() are better names >> for the feature. For example, compatibility for other databases. >> > > I prefere a new names - because there are a new behave - with little > bit better default handling of NULL values. string_to_array and > array_to_string just ignore NULL values - what isn't correct behave.
it is related to time where pg arrays doesn't support a NULL. From 8.3 pg array can have a NULL values, but there wasn't any equal changes to string_to_array and array_to_string functions - so these functions are not "actual". pavel > Later we can mark these functions as deprecated and remove it. If I > use current function, then we have to continue in current behave. > >> * string_to_array( str text, sep text, nullstr text DEFAULT NULL ) >> is compatible with the existing string_to_array( str, sep ), and >> "nullstr => 'NULL'" will be same as your to_array(). >> >> * array_to_string( arr anyarray, sep text, nullstr text DEFAULT NULL ) >> is compatible with the existing array_to_string(); separator also ignored >> when nullstr is NULL. "nullstr => ''" (an empty string) will be same as >> your to_array(). >> > > so reason for these new names are different default behave. And we > can't to change of default behave of existing functions. > > Regards > > Pavel Stehule > > > >> -- >> Itagaki Takahiro >> > -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers