create_user_stmt ::=
	'CREATE' 'USER' name 'WITH' 'PASSWORD' password
	| 'CREATE' 'USER' name  'PASSWORD' password
	| 'CREATE' 'USER' name 
	| 'CREATE' 'USER' 'IF' 'NOT' 'EXISTS' name 'WITH' 'PASSWORD' password
	| 'CREATE' 'USER' 'IF' 'NOT' 'EXISTS' name  'PASSWORD' password
	| 'CREATE' 'USER' 'IF' 'NOT' 'EXISTS' name 
