MYSQL search result - php

Question

I have a code, in which there are users will search for the name from MySQL.
First the mysql should search in first_name, then go to last_name for the same search option and then display results. (From both First_name and Last_name)
I tried but it showed me only the results from first name
Please help me.
Here is the code:-
try {
$keyword = trim($_GET["keyword"]);
if ($keyword <> "" ) {
$sql = "SELECT * FROM tbl_contacts WHERE 1 AND "
. " (first_name LIKE :keyword) ORDER BY first_name ";
$stmt = $DB->prepare($sql);
$stmt->bindValue(":keyword", $keyword."%");
} elseif ($keyword <> "" ) {
$sql = "SELECT * FROM tbl_contacts WHERE 1 AND "
. " (last_name LIKE :keyword) ORDER BY first_name ";
$stmt = $DB->prepare($sql);
$stmt->bindValue(":keyword", $keyword."%");
}else {
$sql = "SELECT * FROM tbl_contacts WHERE 1 ORDER BY first_name ";
$stmt = $DB->prepare($sql);
}
$stmt->execute();
$total_count = count($stmt->fetchAll());

Answer 1

Try to avoid posting same question in other ways, edit the same question.
You asked the same question in MYSQL OR not working
Hope this will really help you:-
try {
$keyword = trim($_GET["keyword"]);
if ($keyword <> "" ) {
$sql = "SELECT * FROM tbl_contacts WHERE 1 AND "
. " (first_name LIKE :keyword OR last_name LIKE :keyword) ORDER BY first_name ";
$stmt = $DB->prepare($sql);
$stmt->bindValue(":keyword", $keyword."%");
}else {
$sql = "SELECT * FROM tbl_contacts WHERE 1 ORDER BY first_name ";
$stmt = $DB->prepare($sql);
}
$stmt->execute();
$total_count = count($stmt->fetchAll());
I have also answered your new repeated question https://stackoverflow.com/a/44859408/7678788