concatenation = = transaction ?????

Hi everybody

It's my first post here, so be indulgent ;)

Just to confirm :  if i do

$sql1='insert into "Enfant"  ("NomEnfant","PrenomEnfant") VALUES
('.$NomEnfant.','.$PrenomEnfant.')

$sql2='insert into "IndividuEnfant" ("IdIndividu","IdEnfant") VALUES
('.$IdIndividu.',currval(\'"Enfant_Seq"\'));

$sql=$sql1.$sql2;

$Res=pg_query($sql);

so 2 query concatenation a a only one, send to postgress database : is it
EXACTLY the same thing than a classic transaction with a begin and a commit
or rollback  ?

Tcks, it's just i dont want to write everything again in 6 months.....

S.L.

PS : why limitation to 8 patrameters in stored procedures ??????