PHP中的多个数据库连接

Question

My requirement is to query two databases. Both the databases are in different hosts. I have created two database connections con1 and con. If the query returns null for con1 then it would fetch data from con. But the code is not working as expected. Any help on the same would be greatly appreciated. I am getting resource id #18 stored in get bookings even though the data is not present for the same in for database connected through con1. Please help.

This is the code that i have written in php.

$get_bookings = mysql_query($SqlQry,$con1);

if (!$get_bookings) 
{
    $get_bookings = mysql_query($SqlQry,$con);
}

Data is mutually exclusive so both connections must be active .

Answer 1

Only connect to the second/backup database until you actually need it. Additionally if you want to check if you got results back from a query use mysql_num_rows()

"mysql_query returns false if there is an error not if there are no results"

if ( mysql_num_rows( $get_bookings ) > 0 ) //do something with results

Answer 2

You're not checking what you think your're checking. Your're only checking if the query ran , not if it actually matched any rows. You need to do need something like mysql_num_rows to see if any data was returned.