Can't PDO with multiple select LIKE - php

Question

Having trouble with the following code. It's not giving an error nor does it output anything. The problem is with the multipleReg part. If I remove bindValue multiplereg and replace :multiplereg in the select statement with $multipleReg it works. I have a feeling it's cause it's not an array but I've tried executing it as an array which has not worked. Any help would be much appreciated.
<?php
header('Content-Type: application/json; Charset=UTF-8');
require "includes/config.php";
$offset = $_GET["offset"];
$region = trim($_GET["region"]);
$regionExp = explode(",", $region);
$tag = $_GET["tag"];
$data = array();
foreach ($regionExp as $singleReg)
$queryKeyword[] = "'%$singleReg%'";
$multipleReg = implode(' OR region LIKE ', $queryKeyword);
try {
$sql = "SELECT * FROM news WHERE FIND_IN_SET(`tag`, :tag) AND
(region LIKE :multipleReg) ORDER BY id DESC LIMIT 10 OFFSET :offsetNr";
$stmt = $db->prepare($sql);
$stmt->bindValue(':tag', $tag);
$stmt->bindValue(':multipleReg', $multipleReg);
$stmt->bindValue(':offsetNr', (int) $offset, PDO::PARAM_INT);
$stmt->execute();
while($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
$data[] = $row;
}
echo json_encode($data);
$stmt->closeCursor();
exit();
} catch(PDOException $e) {
echo $e->getMessage();
}
?>

Answer 1

You could create an array to prepare your SQL string and another to store placeholders :
$qstr = [];
foreach ($regionExp as $k => $singleReg) {
$queryKeyword[':lk'.$k] = "%$singleReg%";
$qstr[] = 'region LIKE :lk'.$k ;
}
Then your SQL query (don't forget to check if $qstr is not empty) :
$sql = "SELECT * FROM news WHERE FIND_IN_SET(`tag`, :tag)
AND (".implode(' OR ', $qstr).")
ORDER BY id DESC LIMIT 10 OFFSET :offsetNr";
And to bind :
// Instead of : $stmt->bindValue(':multipleReg', $multipleReg);
foreach ($queryKeyword as $k => $v) $stmt->bindValue($k, $v);
EDIT The full code :
$offset = $_GET["offset"];
$region = trim($_GET["region"]);
$regionExp = explode(",", $region);
$tag = $_GET["tag"];
// This part has changed :
$qstr = [];
foreach ($regionExp as $k => $singleReg) {
$queryKeyword[':lk'.$k] = "%$singleReg%";
$qstr[] = 'region LIKE :lk'.$k ;
}
try {
// The SQL string changed
$sql = "SELECT * FROM news WHERE FIND_IN_SET(`tag`, :tag)
AND (".implode(' OR ', $qstr).")
ORDER BY id DESC LIMIT 10 OFFSET :offsetNr";
// Debug (see below)
// echo $sql."\n" ;
// print_r($queryKeyword);
$stmt = $db->prepare($sql);
$stmt->bindValue(':tag', $tag);
// The line below replaced
foreach ($queryKeyword as $k => $v) $stmt->bindValue($k, $v);
$stmt->bindValue(':offsetNr', (int) $offset, PDO::PARAM_INT);
$stmt->execute();
$data = array();
while($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
$data[] = $row;
}
echo json_encode($data);
$stmt->closeCursor();
exit();
} catch(PDOException $e) {
echo $e->getMessage();
}
The SQL and dump will look like this :
SELECT * FROM news WHERE FIND_IN_SET(`tag`, :tag)
AND (region LIKE :lk0 OR region LIKE :lk1)
ORDER BY id DESC LIMIT 10 OFFSET :offsetNr
Array
(
[:lk0] => %test%
[:lk1] => %test2%
)