php - Fatal error Call to a member function prepare() on null -

i trying check if email used in registration. worked when working on in school shows error:

fatal error: call member function prepare() on null

i use include

define("dbserver", "localhost"); define("dbuser", "user"); define("dbpass", ""); define("dbname", "user");       $db = new pdo( "mysql:host=" .dbserver. ";dbname=" .dbname,dbuser, array( pdo::mysql_attr_init_command => "set names utf8", pdo::mysql_attr_init_command => "set character set utf8" ) ); 

in here

session_start(); include "dbjoin.php"; if(isset($_post["email"])) {   $_session['email'] = $_post["email"];   }    if(isset($_post["nick"])) {   $_session['nick'] = $_post["nick"];          }     if(isset($_post["pass"])) {   $_session['pass'] = $_post["pass"];   $_session['pass'] = base64_encode($_session['pass']);     } $sthandler = $db->prepare("select email registrace email =     :email"); $sthandler->bindparam(':email', $_session['email']); $sthandler->execute();                if(filter_var($_session['email'], filter_validate_email)) { if($sthandler->rowcount() > 0){       echo "email used";} 

edit: (i figured out).

i figured out why code not working , original answer no longer applies, have stricken out.

the reason why connection not work, because left out dbpass constant connection parameter.

$db = new pdo( "mysql:host=" .dbserver. ";dbname=" .dbname,dbuser,dbpass, array( pdo::mysql_attr_init_command => "set names utf8", pdo::mysql_attr_init_command => "set character set utf8" ) ); 

• even though may not have password set it, still required part of parameters.

• http://php.net/manual/en/ref.pdo-mysql.connection.php

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original answer, no longer applies. (see edit above).

tbh, wasn't able reproduce error, amidst great effort.

however; after tinkering this, have discovered pdo (least, 1 on server), won't allow constants used first 2 parameters in dsn.

sidenote: if worked @ school, there may setting used don't know about.

you can however, assign variables constants, use variables in dsn.

$servername = "localhost"; $dbname = "user";  define("dbuser", "user"); define("dbpass", "");  $dsn = "mysql:host=$servername;dbname=$dbname";  $username = dbuser; // variable equals constant $password = dbpass; // variable equals constant  $options = array( pdo::mysql_attr_init_command => "set names utf8", pdo::mysql_attr_init_command => "set character set utf8" );   $db = new pdo($dsn, $username, $password, $options); 

for more information on pdo connection, visit:

• http://php.net/manual/en/ref.pdo-mysql.connection.php

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add error reporting top of file(s) find errors.

<?php  error_reporting(e_all); ini_set('display_errors', 1);  // rest of code 

sidenote: error reporting should done in staging, , never production.