[pg] To support CREATE/DROP DATABASE

[VWagen1989]

postgres=# CREATE DATABASE IF NOT EXISTS "regression";
ERROR:  Parser Error: syntax error at or near "DATABASE" (errno 1105) (sqlstate HY000)
postgres=# DROP DATABASE IF EXISTS "regression";                                                                                                                                                                                                                                         ERROR:  Parser Error: syntax error at or near "DATABASE" (errno 1105) (sqlstate HY000)