Check if username exist/activated in database using MYSQLi [duplicate]

问题

This question already has an answer here:

Check to see if an email is already in the database using prepared statements (1 answer)

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$username = mysqli_real_escape_string($_POST['username']);

$result = mysqli_query($connect, "SELECT * FROM account WHERE username='".$username."' AND activate='0'");

while($row = mysqli_fetch_assoc($result)) {
    echo 'Account not activated.';
}

I'm new to MYSQLi and I need help on how do I show an error if the user enter a wrong username and its not activated. So far I got the code above.

回答1:

try this

  $username = mysqli_real_escape_string($_POST['username']);

  $result = mysqli_query($connect, "SELECT * FROM account WHERE username='".$username."' AND activate='0'");

  if ($result->num_rows) {
echo "you are activated !!";
                          } 

   else
  {
  // do what u like here if not activated
    }

来源：https://stackoverflow.com/questions/15461765/check-if-username-exist-activated-in-database-using-mysqli