> From: Albe Laurenz [mailto:laurenz.albe@xxxxxxxxxx] > > > > I am attempting to create a new language implementation. The > > > > language is Andl (andl.org), so the handler is plandl. > > > > This is a question about executing SPI queries from inside plandl. > > > > > > > > The documentation makes it clear that SPI allows nested queries; > > > > that in some instances it will be necessary to call SPI_push() and > > > > SPI_pop(), but in others this will be handled automatically. Se > > > http://www.postgresql.org/docs/9.5/interactive/spi-spi-push.html. > > > > > > > > It is an important design feature of plandl to allow nested queries. > > > > > > > > My question is: where are the transaction boundaries if the > > > > inner/outer query do or do not contain BEGIN/ABORT/COMMIT? Do they > > > > nest, or does an inner COMMIT finish a transaction started by an > > > > outer > > > BEGIN, or is it ignored? > > > > > > You cannot have BEGIN or COMMIT inside a function. > > > > Are you sure you meant it like that? I already have BEGIN/COMMIT > > inside a function and it works perfectly. If it did not, then it would > > be impossible to use BEGIN/COMMIT in any language handler, since every call > to a language handler is a call to a function. > > > > Did you mean 'inside a nested function'? Or something else? > > I guess I'm out of my depth when it comes to language handlers... > > But I cannot see how you can have BEGIN or COMMIT called from inside one. > > Doesn't it look like that: > > BEGIN; > SELECT my_andl_function(); > COMMIT; > > Since there are no autonomous transactions in PostgreSQL, how can you have > BEGIN and COMMIT called from the code that is invoked by "SELECT > my_andl_function()"? I really don't know. But I have code that does this (no explicit BEGIN): SELECT * FROM COMPILE($$ V6 := {{ abo:=true, abi:=b'DEADBEEF', anu:=123456789.987654321, ate:='abcdef', ati:=t'2015-12-31 23:59:58.9999' }, { abo:=false, abi:=b'DEADBEEF', anu:=987654321.123456789, ate:='ghijklmno', ati:=t'2016-12-31 23:59:58.9999' }} V6 $$); And the generated code (which executes without error): BEGIN; DROP TABLE IF EXISTS "V6" ; CREATE TABLE "V6" ( "abo" BOOLEAN, "abi" BYTEA, "anu" NUMERIC, "ate" TEXT, "ati" TIMESTAMP, UNIQUE ( "abo", "abi", "anu", "ate", "ati" ) ); COMMIT; INSERT INTO "V6" ( "abo", "abi", "anu", "ate", "ati" ) VALUES ( $1, $2, $3, $4, $5 ); SELECT "abo", "abi", "anu", "ate", "ati" FROM "V6"; Maybe the generated BEGIN/COMMIT are ignored? I haven't tried an ABORT yet. Regards David M Bennett FACS Andl - A New Database Language - andl.org -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
