比较来自MySQL的两个表

Question

I have to compare two tables , then list all of them as check boxes, while matched values should be checked and non matching without checked

//table 1

rid| role_name  
1  |    school  
2  |    college  
3  |  University  

//table2

id|rid | category  
1 | 1  |  uniform  
2 | 2  |  uniform

match rid from both table where category = 'uniform' list all and checked the matching rid

Answer 1

$query = "select a.* from table1 a, table b where a.rid = b.rid and a.category = b.category";

$result = mysqli->query($query);

$fetched = $result->fetch_assoc();

foreach($fetched as $row){
echo "<input type='checkbox' name='{$row['rid']}' value='' checked > {$row['category']}";
}

Answer 2

    $query = "select t1.rid, 'matched' as matching from table1 t1 where t1.rid  in (
              select rid from table2 where category = 'uniform')
             union
             select t1.rid ,'notmatched' from table1 t1 where t1.rid not in (
             select rid from table2 where category = 'uniform')";
    $result = mysqli->query($query);
    $fetched = $result->fetch_assoc();
    foreach($fetched as $row){
    if($row['matching'] = 'matched'){
           echo "<input type='checkbox' name='{$row['rid']}' value='' checked='checked' >"; }
    else{ 
            echo "<input type='checkbox' name='{$row['rid']}' value=''  >"; }
     }

SQL DEMO