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| author | Peter Eisentraut <peter_e@gmx.net> | 2015-04-26 10:33:14 -0400 |
|---|---|---|
| committer | Peter Eisentraut <peter_e@gmx.net> | 2015-04-26 10:33:14 -0400 |
| commit | cac76582053ef8ea07df65fed0757f352da23705 (patch) | |
| tree | 6ae01041aa61db9d686638b9d4c3ccd30d7c6487 /doc/src/sgml/ref/create_function.sgml | |
| parent | f320cbb615e0374b18836337713239da58705cf3 (diff) | |
| download | postgresql-cac76582053ef8ea07df65fed0757f352da23705.tar.gz postgresql-cac76582053ef8ea07df65fed0757f352da23705.zip | |
Add transforms feature
This provides a mechanism for specifying conversions between SQL data
types and procedural languages. As examples, there are transforms
for hstore and ltree for PL/Perl and PL/Python.
reviews by Pavel Stěhule and Andres Freund
Diffstat (limited to 'doc/src/sgml/ref/create_function.sgml')
| -rw-r--r-- | doc/src/sgml/ref/create_function.sgml | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/doc/src/sgml/ref/create_function.sgml b/doc/src/sgml/ref/create_function.sgml index 20019215351..c5beb166cfa 100644 --- a/doc/src/sgml/ref/create_function.sgml +++ b/doc/src/sgml/ref/create_function.sgml @@ -25,6 +25,7 @@ CREATE [ OR REPLACE ] FUNCTION [ RETURNS <replaceable class="parameter">rettype</replaceable> | RETURNS TABLE ( <replaceable class="parameter">column_name</replaceable> <replaceable class="parameter">column_type</replaceable> [, ...] ) ] { LANGUAGE <replaceable class="parameter">lang_name</replaceable> + | TRANSFORM { FOR TYPE <replaceable class="parameter">type_name</replaceable> } [, ... ] | WINDOW | IMMUTABLE | STABLE | VOLATILE | [ NOT ] LEAKPROOF | CALLED ON NULL INPUT | RETURNS NULL ON NULL INPUT | STRICT @@ -261,6 +262,23 @@ CREATE [ OR REPLACE ] FUNCTION </varlistentry> <varlistentry> + <term><literal>TRANSFORM { FOR TYPE <replaceable class="parameter">type_name</replaceable> } [, ... ] }</literal></term> + + <listitem> + <para> + Lists which transforms a call to the function should apply. Transforms + convert between SQL types and language-specific data types; + see <xref linkend="sql-createtransform">. Procedural language + implementations usually have hardcoded knowledge of the built-in types, + so those don't need to be listed here. If a procedural language + implementation does not know how to handle a type and no transform is + supplied, it will fall back to a default behavior for converting data + types, but this depends on the implementation. + </para> + </listitem> + </varlistentry> + + <varlistentry> <term><literal>WINDOW</literal></term> <listitem> |