Duda en sintáxis mysqli_query

[hhs]

Eso lo puedes ver en el manual:

http://www.php.net/manual/en/mysqli.query.php

Código PHP:

mixed mysqli_query ( mysqli $link , string $query [, int $resultmode = MYSQLI_STORE_RESULT ] )
 

resultmode

Either the constant MYSQLI_USE_RESULT or MYSQLI_STORE_RESULT depending on the desired behavior. By default, MYSQLI_STORE_RESULT is used.

If you use MYSQLI_USE_RESULT all subsequent calls will return error Commands out of sync unless you call mysqli_free_result()

With MYSQLI_ASYNC (available with mysqlnd), it is possible to perform query asynchronously. mysqli_poll() is then used to get results from such queries.

http://www.php.net/manual/en/mysqli.constants.php

MYSQLI_STORE_RESULT For using buffered resultsets
MYSQLI_USE_RESULT For using unbuffered resultsets

Que disfrutes la lectura !