AWS EC2 向 RDS 发送 mysql_query 失败

Question

now I'm using AWS EC2, RDS

I use CentOS 7 in EC2, and install apache and all php package (include php-mysql)

DB security group Inbound set mysql/aurora IP = myEC2instance and outbound set Default All and mysql/aurora IP = myEC2instance

And I tried connect EC2 to RDS - upload php file in my EC2 via filezilla

The source is here

$host = "myinstance.c8rse3unpyyi.ap-northeast-2.rds.amazonaws.com";
$user = "myUsername";
$pass = "myPW";
$dbname = "testDB";
$conn = mysqli_connect($host, $user, $pass, $dbname, 3306);

if ($conn) {
    echo "connect_success";
} else {
        echo "connect_fail";
}

# select
$sql = "INSERT INTO test (NAME, NUM)
        VALUES ('john', '3')";
if (mysql_query($sql)) {
    echo "query_sended!";
} else {
    echo "query_failed..";
};

The result is...

connect_success
Warning: mysql_query(): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2) in /var/www/html/db_connect.php on line 20

Warning: mysql_query(): A link to the server could not be established in /var/www/html/db_connect.php on line 20
query_failed..

mysqli_connect is success but mysql_query cannot send!

I tried more inbound rule ex) All TCP, All ICMP, All UDP to ip - EC2 but failed

How can I worked it?

Answer 1

I found problem.....

Once use mysqli_connect then every query send mysqli_query ..

Sorry and THX