如何限制MySQL查询拒绝的结果？

Question

I have this piece of code and it works great. The only issue is that I will get multiple results at once and I just need the one. Lets say I am looking for account # 2, if I type two into the input box name="id" , I will get all results that have the number 2.. If I want to look for a specific person's name, and I type first name and then I enter another last name.. it will bring the first name I want but it will bring other results with the last name I entered. How can I set a limit on the results I look for so either I get a match or not? I am still learning. thank you

PS. valid to say, no where I can specify LIMIT 1..

$searchFields = []; 

foreach (['id', 'firstname', 'lastname', 'email'] as $searchField) {
    if (!empty($_POST[$searchField])) {

        $searchFields[$searchField] = $_POST[$searchField];
    }
}


if (count($searchFields) > 0) {
    $queryStr = "SELECT * FROM `Demo_Guests` WHERE 0";
    foreach (array_keys($searchFields) as $fieldName) {
        $queryStr .= " OR " . $fieldName . " LIKE :" . $fieldName ;
    }
    //var_dump($queryStr);
    $stmt = $conn->prepare($queryStr);
    foreach($searchFields as $fieldName => $fieldValue) {
        $stmt->bindValue(':'. $fieldName, "%$fieldValue%", PDO::PARAM_STR);
    }
    $stmt->execute();
    $result = $stmt->fetchAll(PDO::FETCH_OBJ);
    //var_dump($result);
} else {
    echo  "";
}

}
catch(PDOException $e){
    echo $e->getMessage();
}
}

Answer 1

You can add LIMIT 1 to the end of $queryStr .

$queryStr = "SELECT * FROM `Demo_Guests` WHERE 0";
foreach (array_keys($searchFields) as $fieldName) {
    $queryStr .= " OR " . $fieldName . " LIKE :" . $fieldName ;
}
$queryStr .= " LIMIT 1";