plv8 is a shared library that provides a PostgreSQL procedural language powered by V8 JavaScript Engine. With this program you can write in JavaScript your function that is callable from SQL.
plv8 is tested with:
- PG: version 9.2, 9.3, 9.4 and 9.5 (maybe older/newer are allowed)
- V8: version 4.4 to 4.10
- g++: version 4.8.2
- clang++
Also all tools that PostgreSQL and V8 require to be built are required if you are building those from source.
There are two ways to build plv8. The first is default make, which depends
on system-installed libv8 and plv8 will be dynamically link to it. The second
is make static, which will download v8 source at a specific version and build
it, and statically link plv8 to it. PGXN install will use the former, while
you can do the latter manually if you have not installed v8 yet.
Once you have built and installed plv8, create the language via:
$ psql -c 'CREATE EXTENSION plv8'
$ psql -c 'CREATE EXTENSION plls'
$ psql -c 'CREATE EXTENSION plcoffee'
in 9.1 or later, or in the prior versions:
$ psql -f plv8.sql
to create database objects.
In mingw64, you may have difficulty in building plv8. If so, try to make the following changes in Makefile.
CUSTOM_CC = gcc
SHLIB_LINK := $(SHLIB_LINK) -lv8 -Wl,-Bstatic -lstdc++ -Wl,-Bdynamic -lm
For more detail, please refer to plv8#29
plv8 supports installcheck test. Make sure set custom_variable_classes = 'plv8' in your postgresql.conf (before 9.2) and run
$ make installcheck
CREATE OR REPLACE FUNCTION plv8_test(keys text[], vals text[])
RETURNS text AS $$
var o = {};
for(var i=0; i<keys.length; i++){
o[keys[i]] = vals[i];
}
return JSON.stringify(o);
$$ LANGUAGE plv8 IMMUTABLE STRICT;
SELECT plv8_test(ARRAY['name', 'age'], ARRAY['Tom', '29']);
plv8_test
---------------------------
{"name":"Tom","age":"29"}
(1 row)
CREATE OR REPLACE FUNCTION plcoffee_test(keys text[], vals text[])
RETURNS text AS $$
return JSON.stringify(keys.reduce(((o, key, idx) ->
o[key] = vals[idx]; return o), {}), {})
$$ LANGUAGE plcoffee IMMUTABLE STRICT;
SELECT plcoffee_test(ARRAY['name', 'age'], ARRAY['Tom', '29']);
plcoffee_test
---------------------------
{"name":"Tom","age":"29"}
(1 row)
CREATE OR REPLACE FUNCTION plls_test(keys text[], vals text[])
RETURNS text AS $$
return JSON.stringify { [key, vals[idx]] for key, idx in keys }
$$ LANGUAGE plls IMMUTABLE STRICT;
SELECT plls_test(ARRAY['name', 'age'], ARRAY['Tom', '29']);
plls_test
---------------------------
{"name":"Tom","age":"29"}
(1 row)
plv8 is hosted on github https://github.com/plv8/plv8
and distributed by PGXN. For more detail, see http://pgxn.org/dist/plv8/doc/plv8.html