SET CONNECTION — select a database connection
SET CONNECTION [ TO | = ] connection_name SET CONNECTION sets the “current”
database connection, which is the one that all commands use
unless overridden.
connection_name A database connection name established by
the CONNECT command.
DEFAULTSet the connection to the default connection.
EXEC SQL SET CONNECTION TO con2; EXEC SQL SET CONNECTION = con1;
SET CONNECTION is specified in the SQL standard.