JSON Array returns null

Question

I have the following php code:

$row=$this->conn->prepare('SELECT * FROM users');  

$row->execute();//execute the query  
$json_data=array();//create the array  
foreach($row as $r)
{  
    $json_array = array();
    $json_array['id'] = $r['id'];  
        $json_array['unique_id'] = $r['unique_id'];  
        $json_array['name'] = $r['name'];  
        $json_array['email'] = $r['email'];  
        $json_array['encrypted_password'] = $r['encrypted_password'];  
        $json_array['salt'] = $r['salt'];  
        $json_array['created_at'] = $r['created_at'];  
        $json_array['updated_at'] = $r['updated_at'];  
        $json_array['phone_number'] = $r['phone_number']; 

    //here pushing the values in to an array  
        array_push($json_data,$json_array);  

}  

//built in PHP function to encode the data in to JSON format  
return json_encode($json_data);

When i run it i am only getting this:

[{"id":null,"unique_id":null,"name":null,"email":null,"encrypted_password":null,"salt":null,"created_at":null,"updated_at":null,"phone_number":null},{"id":null,"unique_id":null,"name":null,"email":null,"encrypted_password":null,"salt":null,"created_at":null,"updated_at":null,"phone_number":null},{"id":null,"unique_id":null,"name":null,"email":null,"encrypted_password":null,"salt":null,"created_at":null,"updated_at":null,"phone_number":null},{"id":null,"unique_id":null,"name":null,"email":null,"encrypted_password":null,"salt":null,"created_at":null,"updated_at":null,"phone_number":null},{"id":null,"unique_id":null,"name":null,"email":null,"encrypted_password":null,"salt":null,"created_at":null,"updated_at":null,"phone_number":null},{"id":null,"unique_id":null,"name":null,"email":null,"encrypted_password":null,"salt":null,"created_at":null,"updated_at":null,"phone_number":null},{"id":null,"unique_id":null,"name":null,"email":null,"encrypted_password":null,"salt":null,"created_at":null,"updated_at":null,"phone_number":null},{"id":null,"unique_id":null,"name":null,"email":null,"encrypted_password":null,"salt":null,"created_at":null,"updated_at":null,"phone_number":null},{"id":null,"unique_id":null,"name":null,"email":null,"encrypted_password":null,"salt":null,"created_at":null,"updated_at":null,"phone_number":null}]

My database contains only 2 users and they don't have null columns.

What is $this->conn ? I believe you need to iterate on something like $row->fetch(), not just $row — mopo922
– mopo922, Commented Jan 5, 2016 at 19:12

VolkerK · Accepted Answer · 2016-01-05 19:36:32Z

1

$row is an instance of mysqli_stmt; you cannot use it directly as a traversable in foreach() like a mysqli_result instance ( PHP >= 5.4.0).

$statement = $this->conn->prepare('
    SELECT
        id,
        unique_id,
        name,
        email,
        encrypted_password,
        salt,
        created_at,
        updated_at,
        phone_number
    FROM
        users
');

if ( !$statement ) {
    yourErrorHandler();
}

if ( !$statemnt->execute() ) {
    yourErrorHandler();
}

$result = $statement->get_result(); // PHP 5 >= 5.3.0,
$json_data=[];
foreach($result as $row) { // PHP 5 >= 5.4.0
    $json_data[] = $row;
}
return json_encode($json_data);

alternative version:

$result = $this->conn->query('
    SELECT
        id,
        unique_id,
        name,
        email,
        encrypted_password,
        salt,
        created_at,
        updated_at,
        phone_number
    FROM
        users
');

if ( !$result ) {
    yourErrorHandler();
}

return json_encode( $result->fetch_all(MYSQLI_ASSOC) );

answered Jan 5, 2016 at 19:36

VolkerK

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3 Comments

Skizzotrick Over a year ago

I've tried the first one and it keeps that i'm callind to undefined method get_results. I've tried fetch and still not working. The alternative version gives me this error: "Call to undefined method mysqli_result::fetch_all()"

Skizzotrick Over a year ago

Nevermind, i've fixed it. I had to manually fetch the result. THANKS ALOT! I've been struggling on this for 2 days. love you!

VolkerK Over a year ago

fetch_all() has been introduced with php 5.3.0, are you still using a version <5.3 ?

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