How can I with mysqli make a query with LIKE and get all results?

Question

This is my code but it dosn't work:

$param = "%{$_POST['user']}%";
$stmt = $db->prepare("SELECT id,Username FROM users WHERE Username LIKE ?");
$stmt->bind_param("s", $param);
$stmt->execute();
$stmt->bind_result($id,$username);
$stmt->fetch();

This code it doesn't seem to work. I have searched it a lot. Also it may return more than 1 row. So how can I get all the results even if it returns more than 1 row?

Answer 1

Here's how you properly fetch the result

$param = "%{$_POST['user']}%";
$stmt = $db->prepare("SELECT id,username FROM users WHERE username LIKE ?");
$stmt->bind_param("s", $param);
$stmt->execute();
$stmt->bind_result($id,$username);

while ($stmt->fetch()) {
  echo "Id: {$id}, Username: {$username}";
}

or you can also do:

$param = "%{$_POST['user']}%";
$stmt = $db->prepare("SELECT id, username FROM users WHERE username LIKE ?");
$stmt->bind_param("s", $param);
$stmt->execute();

$result = $stmt->get_result();
while ($row = $result->fetch_assoc()) {
    echo "Id: {$row['id']}, Username: {$row['username']}";
}

I hope you realise I got the answer directly from the manual here and here , which is where you should've gone first.

Answer 2

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Updated

From comments it is found that LIKE wildcard characters ( _ and % ) are not escaped by default on Paramaterised queries and so can cause unexpected results.

Therefore when using "LIKE" statements, use this 'negative lookahead' Regex to ensure these characters are escaped :

$param = preg_replace('/(?<!\\\)([%_])/', '\\\$1',$param);

---

As an alternative to the given answer above you can also use the MySQL CONCAT function thus:

$stmt = $db->prepare("SELECT id,Username FROM users WHERE Username LIKE CONCAT('%',?,'%') ");
$stmt->bind_param("s", $param);
$stmt->execute();

Which means you do not need to edit your $param value but does make for slightly longer queries.

Answer 3

The answer is obviously outdated, you don't even need to use bind_param.

$querySql    = "SELECT * FROM table WHERE columnName LIKE :likeKeyWord";
$likeKeyWord = "%". $keyWord ."%";
$pdoStm      = $this -> db -> prepare($querySql);
$pdoStm -> execute([':likeKeyWord' => $likeKeyWord]);
return $pdoStm -> fetchAll();