where is the index physically located in MySQL database?

Twitter bot coding fail: is my MySql setup right?

• I have been trying and failing, to code a twitter bot that tweets lines held in a MYSQL database, one by one, in order. I have a DATABASE with two tables:  1. tweetstable - holds a lot of tweets (tweetsfield) and an id column (id)  2. last_row - holds a single number, updated each tweet with the id of last tweeted line I must warn you that this was pasted together from various sources and is probably riddled with errors, or missing entire sections. I am not a coder, I hack stuff together and eventually get stuff working. This time I am WAAAY over my head. The following code should select the id of the last tweeted line:     $last_id = $last_row->id; Then selects the a line from the text table that is greater than then $last_id and is not blank:     $db2->where('id >',$last_id);     $db2->where('tweetsfield !='," "); Then tweets the line, and stores the id of the line back in the database... But it fails miserably. I'm getting this error     Fatal error: Call to a member function where() on a non-object in /LOCATION/index.php on line 13 i.e.     $db2->where('id >',$last_id); Even if I define $db at start as $db2 What am I missing?         <?php         /* database parameters */     $db_host = 'HOST';     $db_user = 'USERNAME';     $db_pw = 'PASSWORD';     $db = 'DATABASE';         mysql_connect($db_host, $db_user, $db_pw) or die('Could not connect to database');     mysql_select_db($db) or die('Could not select database');          $last_id = $last_row->id;     $db2->where('id >',$last_id);     $db2->where('tweetfield !='," ");         $new_last_id = $line->id;     $db2->set('id',$new_last_id);     $db2->update('last_row');         function tweetline() {         $config = array(       'CONSUMER_KEY' => CONSUMER_KEY,       'CONSUMER_SECRET' => CONSUMER_SECRET,       'ACCESS_TOKEN' => ACCESS_TOKEN,       'ACCESS_TOKEN_SECRET' => ACCESS_TOKEN_SECRET     );         $this->load->library('TwitterOAuth',$config);     $twitter = new TwitterOAuth($config);         $db2 = $this->load->database('DATABASE', TRUE);     $last_row = $db2->get('last_row');     $last_row = $last_row->row();     $last_id = $last_row->id;         $db2->where('id >',$last_id);     $db2->where('tweetfield !='," ");     $db2->limit(1);     $aline = $db2->get('tweetstable');     if ($aline->num_rows() > 0) {     $line= $aline->row();     $tweet = $line->tweetfield;     // tweet the tweet     $twitter->post('statuses/update',array('status' => $tweet));     sleep(1);     $db2 = $this->load->database('last_row', TRUE);         $new_last_id = $line->id;     $db2->set('id',$new_last_id);     $db2->update('last_row');     die();     }         }     ?>

• Answer:

  Fatal error: Call to a member function where() on a non-object in /LOCATION/index.php on line 13 means that $db2 is not an object. $db2 is a string. it contains the word "DATABASE".  (if you define $db at start as $db2. If you don't, then $db is undefined!). So yeah, your MySQL setup is definitely not right!