php mysql for循环

Question

in my query i want only from id 1-3 to appear in the result, not 4-6. is there any other way to do it?

beautician database table:
id_beautician   name
1               a
2               b
3               c
4               d
5               e
6               f

i tried to put the code below in mysql query

for($i=4; $i<=6; $i++) :
    $q.$i = $db->query("SELECT * FROM beautician WHERE id_beautician='$i'");
    $r.$i = $q.$i->fetch_assoc();
    //echo $i;
endfor;

but it gives me an error:

Object of class mysqli_result could not be converted to string

Answer 1

If ids are not in sequence, you can also use as below.

$query = $db->query("SELECT * FROM beautician WHERE id_beautician in (1,2,3)");
while ( $row = $query->fetch_assoc() ) 
{
    echo $row['id'] . ' = ' . $row['name'] . '<br/>';
}

using IN in query sometimes slow down the execution, but can be used efficiently for small-size database.