execute
Executes a statement with no result and no row count — DDL, SET, administrative commands.
This method speaks the Simple Query Protocol and takes no parameters at all: the SQL is sent exactly as written, so any placeholders (like $1 or @name) in it reach the server as literal text rather than being substituted. It accepts a whole script of statements separated by ; in a single round trip, which PostgreSQL wraps in an implicit transaction.
Parameters
Whether a statement returning rows may pass. Rows are discarded either way and there is no reading them from here; what this decides is whether their arrival is reported. Left false, execute("SELECT …") — a query sent where fetchRows was meant — is caught instead of quietly doing nothing, which is worth keeping. Set it where the SQL is a script somebody else wrote and a SELECT in it is legitimate: pg_dump emits SELECT pg_catalog.setval(...) for every sequence it carries.
Throws
UNEXPECTED_RESULT if any statement in the SQL returned rows and ignoreRows is false.