Count function is not working properly for sql's result-CodePudding

I wrote code for sign up where I check username , if it is exists in database or not than add new user accordingly. I am new to sql->prepare statement, Problem is in count function , when checking username it works properly, but in else part when adding user it gives me following error

Uncaught TypeError: count(): Argument #1 ($value) must be of type Countable|array, bool

Here is my adduser.php code.

<?php 

 include 'config.php';

 //checkusername

 $check = $con->prepare("select username from users where username = ?");
 $check->bindParam(1,$username);
 $username = $_POST['username'];
 $check->execute();
 $row = $check->fetch(PDO::FETCH_ASSOC);

     if(count($row)){
       echo -1;
  
     }
     
     else{

        $sql = $con->prepare("insert into users(name,username,password) values(?,?,?)");
        $sql->bindParam(1,$name);
        $sql->bindParam(2,$username);
        $sql->bindParam(3,$password);
        $name = $_POST['name'];
        $username = $_POST['username'];
        $password = md5($_POST['password']);
        $sql->execute();
            echo 1;
     }

 ?>

CodePudding user response：

It doesn't make much sense to use count here, you don't need to know how many fields are in the row.

Just check if it's false or not - see php.net/manual/en/pdostatement.fetch.php which mentions that fetch() will return false when it fails (i.e. there is no row available).

This would make more sense:

if($row) {
    $sql = $con->prepare("insert into users(name,username,password) values(?,?,?)");
    //...etc...
}
else {
   echo -1;
}

CodePudding user response：

After executing the query with $check->execute();, you can use the built-in method to count the returned rows: $check->rowCount();.

I think the statement above returned 0 rows, so you can't do $check->fetch() and it returns false.

Example:

// Your code here...
$check = $con->prepare("select username from users where username = ?");
$username = $_POST['username']; // This line needs to be before the next one, because you used the variable $username before defining it
$check->bindParam(1,$username);
$check->execute();
if($check->rowCount() > 0) {
  // User does exist
} else {
  // User does not exist
}

CodePudding user response：

Edit 2: I just realised that the answer I've given below is wrong. The thing I suggest instead is checking if there's any value by using the PDO rowCount() method, like this: if ($check->rowCount()>0)

wrong stuff below
You're assigining $username a value after binding it.

 $check = $con->prepare("select username from users where username = ?");
 $check->bindParam(1,$username); //bind $username
 $username = $_POST['username']; //assign value
 $check->execute();

Try switching those two lines so $username is assigned a value when you're binding it.

 $check = $con->prepare("select username from users where username = ?");
 $username = $_POST['username']; //assign value
 $check->bindParam(1,$username); //bind $username   
 $check->execute();

Edit In case you're still having issues, try checking if there's any error in the sql statement execution. After your $check->execute(); you can add print_r($check->errorInfo()); to see if your MySQL statement has any issues in it.