sql语法返回mysql_num_rows（）期望参数1是资源，布尔给定[重复]

Question

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• mysql_fetch_array()/mysql_fetch_assoc()/mysql_fetch_row()/mysql_num_rows etc… expects parameter 1 to be resource or result 32 answers

I have the following piece of code. Drives me crazy. Cannot find where is my mistake. Looks like there is a conflict with the use of limit in my sql syntax and the mysql_query in variable $result does not return anything.

<?php

$sql = " select  *  from  `share`  where  (`category` LIKE '$category' and `country` LIKE '$country' and `city` LIKE '%$city_name%' and `job_title` LIKE '%$job_name%' and `user_id`!='$session_user_id')  
        order by `share_id` desc LIMIT 3; ";

$result = mysql_query($sql);

if( mysql_num_rows($result) ==0 ){ 
  echo"success";
}

?>

</div>

Answer 1

String concatenation problem that causing issues.

$sql = "select * from `share`
        where
          (`category` LIKE '". $category ."'
            and `country` LIKE '". $country ."'
            and `city` LIKE '%". $city_name ."%'
            and `job_title` LIKE '%". $job_name ."%'
            and `user_id` != '". $session_user_id ."')
        order by `share_id` desc
       limit 3";