如何检查数据库行中是否同时存在 $_POST['name']=name 和 $_POST['phone']=phone?

HOW DO I CHECK IF BOTH $_POST['name']=name AND $_POST['phone']=phone exist in a db row?

if('SELECT * FROM users WHERE firstname='$_POST['firstname']' AND WHERE 
phone='$_POST['phone']''){echo 'their is a match';}

解析错误:语法错误,意外T_VARIABLE

假设您正在使用面向对象的 MySQLI,您的代码将如下所示:

$phone = ( isset( $_POST['phone'] ) && !empty( $_POST['phone'] ) ) ? $conn->real_escape_string( $_POST['phone'] ) : null;
$firstname = ( isset( $_POST['firstname'] ) && !empty( $_POST['firstname'] ) ) ? $conn->real_escape_string( $_POST['firstname'] ) : null;

//create the mysql query
$sql = "SELECT * FROM users WHERE firstname='$firstname' AND phone='$phone'";

$result = $conn->query($sql); //query the database

if ($result->num_rows > 0) { //check if there are any results
   echo "There is a match.";
} else {
   echo "No matches.";
}