通过php [duplicate]检查mysql_query的结果中是否有条目

I'm very new here as well as in php and mysql and I hope you can help me :)

I'm trying to build a JSON for a visualization using data from a database. My problem is, that it doesn't passes the if-request. In the while-loop the data should be used row by row in a certain way but before that, there have to be done something else. But everthing ONLY if there is any row in the result.

Following code is relevant for my issue:

            //get data where a value fits former input
            $query = "SELECT * FROM table1 WHERE column1 = '" . $input. "'";
            $data = mysql_query($query) or die (mysql_error());

            if ( mysql_num_rows(data) > 0){
            //if($data != NULL){ (didn't work either)

                //do something

                while($data_Row = mysql_fetch_array($data)){

                    //do something

                }
            }

I hope you understood the issue (not sure whether I was able to make it clear). I already tested several solutions from diverse sites but nothing worked so far.

I would appreciate your help :)

</div>

Try this

if ($data){
    while($row = mysql_fetch_array($data)){
        //do stuff
    }
}