如何强制重新连接到 php 中的数据库？

Question

I wanted my web system to automatically reconnect to the database if it reaches to maximum user connection. Or is there anyway i could reload the page automatically till it is connected to the database

$conn =  new mysqli(DB_HOST,DB_USER,DB_PSWD,DB_NAME);

if($conn->connect_error)
die("Failed to connect database ".$conn->connect_error );

Answer 1

You can setting the retry variable( $retry ) as a flag to mark the DB connection status with default value you want. While connect DB, if it's ok then update retry flag = 0( $retry=0 ), else reduce the retry one unit ( $retry-- ). Also you don't die process when have error exception.

Answer 2

You can enclose the connection in a function and call it many times you want to retry the connection:

function connectDB(DB_HOST,DB_USER,DB_PSWD,DB_NAME)
{
    return $conn = new mysqli(DB_HOST,DB_USER,DB_PSWD,DB_NAME);
}


if(connectDB()->connect_error)
{
    sleep(1);
    if(connectDB()->connect_error)
    {
        die("Failed to connect database ".$conn->connect_error );
    }
}

With sleep(1) you delay the script to retry the connection after 1 second.

Anyway, you should find the cause of the connection error and solve it; this solution may help you in the case the server is sometimes slow to respond.