php - How can I check if a value already exists in mySQL database? -

i want store name in mysql database. when click submit button, php should check if name exists in database. if yes not submit , print error message:

name exists in database.

<?php      if ( !empty($_post)) {              $name = $_post['name'];              $valid = true;              if ($valid) {                 $pdo = database::connect();                 $pdo->setattribute(pdo::attr_errmode, pdo::errmode_exception);                 $sql = "insert people (name) values(?) ";                 $q = $pdo->prepare($sql);                 $q->execute(array($name));              }         }     ?>      <form action="form.php" method="post">           <input name="name" type="text"  value="<?php echo !empty($name)?$name:'';?>">           <button type="submit" >submit</button>                     </form> 

try following query check if value exists in mysql database?

$q = $pdo->prepare("select name people name = :name limit 1"); $q->bindvalue(':name', '$name'); $q->execute();  if ($q->rowcount() > 0){     $check = $q->fetch(pdo::fetch_assoc);     $row = $check['name'];     // if name exist } else {     // if name doesn't exist }