How to pass any value in parameterised query in mysqli?

Question

Objective: to pass any value in where phrase of mysqli parameterised query

code:

<?php
$name="%%";
$age="%%";
$name_op=null;
$age_op=null;
require_once("dbc.php");
$query="SELECT name, age from student WHERE name LIKE ? AND age LIKE ?";
$stmt=mysqli_prepare($dbc, $query);
mysqli_bind_param($stmt, "si", $name, $age);
mysqli_stmt_execute($stmt);
mysqli_bind_result($stmt, $name_op, $age_op);
while(mysqli_bind_fetch($stmt)){
echo "name : $name_op age: $age_op";
}
mysqli_stmt_close($stmt);
mysqli_close($dbc);
?>

Observation: In mysql prompt,

mysql> SELECT name, age from student WHERE name LIKE  "%%" AND age LIKE "%%";

shows all the records.

But, the above php code doesn't display any record.

Please help me in passing any value in parameterised query.

Answer 1

Under "any" value you are assuming any string value. Hence, you must use the correct type: s, not i for the $age variable.

<?php
require_once("dbc.php");

$name="%%";
$age="%%";

$query = "SELECT name, age from student WHERE name LIKE ? AND age LIKE ?";
$stmt = $dbc->prepare($query);
$stmt->bind_param("ss", $name, $age);
$stmt->execute();
$result = $stmt->get_result();
while($row = $result->fetch_assoc()){
    echo "name : $row[name] age: $row[age]";
}