mysqli num_rows嵌套查询

Question

I'm updating a site from MySQL to MySQLi, using OOP.

For the most part things are going well, but this line is giving me divine trouble:

$pager_total = mysql_num_rows(mysql_query($MySQLctr,$MyDB));

I've tried

$pager_total = $MyDB->query($MySQLctr)->num_rows;
and
$pager_total = ($MyDB->query($MySQLctr))->num_rows;
and
$new_object = $MyDB->query($MySQLctr);
$pager_total = $new_object->num_rows;

but no avail.

Any thoughts?

Answer 1

OOP mysqli is very simple :) try this example

$DBH=new mysql('location of database','username','password','database');
$get=$DBH->prepare('SELECT COUNT(*) FROM table');//notice the count(*) in the query, it's not the same as mysql_num_row() but works in the same way
//prepare is also a more secure way of processing query, please look up the difference between prepare and query though.
//$DBH->prepare('SELECT * FROM table WHERE ID=2'); will not work.
$get->execute();//execute the above prepared statement
$get->bind_result($count);//get the result of the query, should be whatever COUNT(*) returns
$get->close();//don't forget to close your connection

The mysqli of mysql_num_row() is $query->num_rows().

I added a little bit extra to get you started with OOP mysqli :) Notice though that I didn't use $get->num_rows() but COUNT(*) instead for a more simple example. Here is another method you may be more familiar with:

$counter=$DBH->query('SELECT * FROM table');
echo$counter->num_rows();

Also see here for more examples.