2009/8/9 Alvaro Herrera <alvhe...@commandprompt.com>: > Jeff Davis escribió: >> On Mon, 2009-04-20 at 18:53 +0200, Pavel Stehule wrote: >> > b) it allows constructors for data types (ANSI SQL) >> > >> > datatype(typefield1[, typefiedl2[, typefiedl3[, ...]]]) returns type >> >> Can you describe this case in more detail? What section of SQL are you >> referring to? > > Hmm, I see them in 4.7 "user-defined types". However what's in SQL2003 > and the 2008 draft I have is: > > 3.1.6.6 constructor function: A niladic SQL-invoked function of which exactly > one is implicitly specified for every structured type. An invocation of the > constructor function for data type T returns a value V of the most specific > type T such that V is not null and, for every observer function O defined for > T, the invocation O(V) returns the default value of the attribute > corresponding > to O. > > and later: > > 4.7.4 Constructors > Associated with each structured type ST is one implicitly defined constructor > function, if and only if ST is instantiable. > Let TN be the name of a structured type T. The signature of the constructor > function for T is TN() and its result data type is T. The invocation TN() > returns a value V such that V is not null and, for every attribute A of T, > A(V) > returns the default value of A. The most specific type of V is T. > For every structured type ST that is instantiable, zero or more SQL-invoked > constructor methods can be specified. The names of those methods shall be > equivalent to the name of the type for which they are specified. >
yes - it is Thank You > So I'm not seeing those typefields anywhere. > > -- > Alvaro Herrera http://www.CommandPrompt.com/ > PostgreSQL Replication, Consulting, Custom Development, 24x7 support > -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
