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Database connection class!





James007
I've found this database connection class on hotscripts, and it works just fine on my pc, but it doesn't work online.

It must have something to do with the mysql version being quite old on the server (MySQL 3.23.58-log).

Now tell me, anyone! What part of the script can cause the error:
Quote:
db.class.php Error:
No Database Selected


Login variables are correct.

Code:
<?php
/*******************************************************************************
 *                         MySQL Database Class
 *******************************************************************************
 *      Author:     Micah Carrick
 *      Email:      email@micahcarrick.com
 *      Website:    http://www.micahcarrick.com
 *
 *      File:       db.class.php
 *      Version:    1.0.4
 *      Copyright:  (c) 2005 - Micah Carrick
 *                  You are free to use, distribute, and modify this software
 *                  under the terms of the GNU General Public License.  See the
 *                  included license.txt file.
 *     
 *******************************************************************************
 *  VERION HISTORY:
 * 
 *      v1.0.4 [07.06.2005] - Added ability to add NULL values in update_array
 *                            and insert_array functions.
 *      v1.0.3 [05.10.2005] - Fixed bug in update_array funciton
 *      v1.0.2 [05.09.2005] - Fixed select_one function for queries returning 0
 *      v1.0.1 [04.28.2005] - Fixed bug in select_one function (returned null!)
 *      v1.0.0 [04.17.2005] - Initial Version
 *
 *******************************************************************************
 *  DESCRIPTION:
 *
 *      This class aids in MySQL database connectivity. It was written with
 *      my specific needs in mind.  It simplifies the database tasks I most
 *      often need to do thus reducing redundant code.  It is also written
 *      with the mindset to provide easy means of debugging erronous sql and
 *      data during the development phase of a web application.
 *
 *      The future may call for adding a slew of other features, however, at
 *      this point in time it just has what I often need.  I'm not trying to
 *      re-write phpMyAdmin or anything.  :)  Hope you find it  useful.
 *
 *      A screenshot and sample script can be found on my website.
 *
 *******************************************************************************
 */

// constants used by class
define('MYSQL_TYPES_NUMERIC', 'int real ');
define('MYSQL_TYPES_DATE', 'datetime timestamp year date time ');
define('MYSQL_TYPES_STRING', 'string blob ');

class db_class {
 
   var $last_error;         // holds the last error. Usually mysql_error()
   var $last_query;         // holds the last query executed.
   var $row_count;          // holds the last number of rows from a select
   
   var $host;               // mySQL host to connect to
   var $user;               // mySQL user name
   var $pw;                 // mySQL password
   var $db;                 // mySQL database to select

   var $db_link;            // current/last database link identifier
   var $auto_slashes;       // the class will add/strip slashes when it can
   
   function db_class() {
   
      // class constructor.  Initializations here.
     
      // Setup your own default values for connecting to the database here. You
      // can also set these values in the connect() function and using
      // the select_database() function.
     
      $this->host = 'localhost';
      $this->user = 'root';
      $this->pw = '';
      $this->db = 'site';
 
      $this->auto_slashes = true;
   }

   function connect($host='', $user='', $pw='', $db='', $persistant=true) {
 
      // Opens a connection to MySQL and selects the database.  If any of the
      // function's parameter's are set, we want to update the class variables. 
      // If they are NOT set, then we're giong to use the currently existing
      // class variables.
      // Returns true if successful, false if there is failure. 
     
      if (!empty($host)) $this->host = $host;
      if (!empty($user)) $this->user = $user;
      if (!empty($pw)) $this->pw = $pw;

 
      // Establish the connection.
      if ($persistant)
         $this->db_link = mysql_pconnect($this->host, $this->user, $this->pw);
      else
         $this->db_link = mysql_connect($this->host, $this->user, $this->pw);
 
      // Check for an error establishing a connection
      if (!$this->db_link) {
         $this->last_error = mysql_error();
         return false;
      }
 
      // Select the database
      if (!$this->select_db($db)) return false;
 
      return $this->db_link;  // success
   }

   function select_db($db='') {
 
      // Selects the database for use.  If the function's $db parameter is
      // passed to the function then the class variable will be updated.
 
      if (!empty($db)) $this->db = $db;
     
      if (!mysql_select_db($this->db)) {
         $this->last_error = mysql_error();
         return false;
      }
 
      return true;
   }
   
   function select($sql) {
     
      // Performs an SQL query and returns the result pointer or false
      // if there is an error.
 
      $this->last_query = $sql;
     
      $r = mysql_query($sql);
      if (!$r) {
         $this->last_error = mysql_error();
         return false;
      }
      $this->row_count = mysql_num_rows($r);
      return $r;
   }

   function select_one($sql) {
 
      // Performs an SQL query with the assumption that only ONE column and
      // one result are to be returned.
      // Returns the one result.
 
      $this->last_query = $sql;
     
      $r = mysql_query($sql);
      if (!$r) {
         $this->last_error = mysql_error();
         return false;
      }
      if (mysql_num_rows($r) > 1) {
         $this->last_error = "Your query in function select_one() returned more that one result.";
         return false;     
      }
      if (mysql_num_rows($r) < 1) {
         $this->last_error = "Your query in function select_one() returned no results.";       
         return false;
      }
      $ret = mysql_result($r, 0);
      mysql_free_result($r);
      if ($this->auto_slashes) return stripslashes($ret);
      else return $ret;
   }
   
   function get_row($result, $type='MYSQL_BOTH') {
 
      // Returns a row of data from the query result.  You would use this
      // function in place of something like while($row=mysql_fetch_array($r)).
      // Instead you would have while($row = $db->get_row($r)) The
      // main reason you would want to use this instead is to utilize the
      // auto_slashes feature.
     
      if (!$result) {
         $this->last_error = "Invalid resource identifier passed to get_row() function.";
         return false; 
      }
     
      if ($type == 'MYSQL_ASSOC') $row = mysql_fetch_array($result, MYSQL_ASSOC);
      if ($type == 'MYSQL_NUM') $row = mysql_fetch_array($result, MYSQL_NUM);
      if ($type == 'MYSQL_BOTH') $row = mysql_fetch_array($result, MYSQL_BOTH);
     
      if (!$row) return false;
      if ($this->auto_slashes) {
         // strip all slashes out of row...
         foreach ($row as $key => $value) {
            $row[$key] = stripslashes($value);
         }
      }
      return $row;
   }
   
   function dump_query($sql) {
   
      // Useful during development for debugging  purposes.  Simple dumps a
      // query to the screen in a table.
 
      $r = $this->select($sql);
      if (!$r) return false;
      echo "<div style=\"border: 1px solid blue; font-family: sans-serif; margin: 8px;\">\n";
      echo "<table cellpadding=\"3\" cellspacing=\"1\" border=\"0\" width=\"100%\">\n";
     
      $i = 0;
      while ($row = mysql_fetch_assoc($r)) {
         if ($i == 0) {
            echo "<tr><td colspan=\"".sizeof($row)."\"><span style=\"font-face: monospace; font-size: 9pt;\">$sql</span></td></tr>\n";
            echo "<tr>\n";
            foreach ($row as $col => $value) {
               echo "<td bgcolor=\"#E6E5FF\"><span style=\"font-face: sans-serif; font-size: 9pt; font-weight: bold;\">$col</span></td>\n";
            }
            echo "</tr>\n";
         }
         $i++;
         if ($i % 2 == 0) $bg = '#E3E3E3';
         else $bg = '#F3F3F3';
         echo "<tr>\n";
         foreach ($row as $value) {
            echo "<td bgcolor=\"$bg\"><span style=\"font-face: sans-serif; font-size: 9pt;\">$value</span></td>\n";
         }
         echo "</tr>\n";
      }
      echo "</table></div>\n";
   }
   
   function insert_sql($sql) {
       
      // Inserts data in the database via SQL query.
      // Returns the id of the insert or true if there is not auto_increment
      // column in the table.  Returns false if there is an error.     
 
      $this->last_query = $sql;
     
      $r = mysql_query($sql);
      if (!$r) {
         $this->last_error = mysql_error();
         return false;
      }
     
      $id = mysql_insert_id();
      if ($id == 0) return true;
      else return $id;
   }

   function update_sql($sql) {
 
      // Updates data in the database via SQL query.
      // Returns the number or row affected or true if no rows needed the update.
      // Returns false if there is an error.

      $this->last_query = $sql;
     
      $r = mysql_query($sql);
      if (!$r) {
         $this->last_error = mysql_error();
         return false;
      }
     
      $rows = mysql_affected_rows();
      if ($rows == 0) return true;  // no rows were updated
      else return $rows;
     
   }
   
   function insert_array($table, $data) {
     
      // Inserts a row into the database from key->value pairs in an array. The
      // array passed in $data must have keys for the table's columns. You can
      // not use any MySQL functions with string and date types with this
      // function.  You must use insert_sql for that purpose.
      // Returns the id of the insert or true if there is not auto_increment
      // column in the table.  Returns false if there is an error.
     
      if (empty($data)) {
         $this->last_error = "You must pass an array to the insert_array() function.";
         return false;
      }
     
      $cols = '(';
      $values = '(';
     
      foreach ($data as $key=>$value) {     // iterate values to input
         
         $cols .= "$key,"; 
         
         $col_type = $this->get_column_type($table, $key);  // get column type
         if (!$col_type) return false;  // error!
         
         // determine if we need to encase the value in single quotes
         if (is_null($value)) {
            $values .= "NULL,";   
         }
         elseif (substr_count(MYSQL_TYPES_NUMERIC, "$col_type ")) {
            $values .= "$value,";
         }
         elseif (substr_count(MYSQL_TYPES_DATE, "$col_type ")) {
            $value = $this->sql_date_format($value, $col_type); // format date
            $values .= "'$value',";
         }
         elseif (substr_count(MYSQL_TYPES_STRING, "$col_type ")) {
            if ($this->auto_slashes) $value = addslashes($value);
            $values .= "'$value',"; 
         }
      }
      $cols = rtrim($cols, ',').')';
      $values = rtrim($values, ',').')';     
     
      // insert values
      $sql = "INSERT INTO $table $cols VALUES $values";
      return $this->insert_sql($sql);
     
   }
   
   function update_array($table, $data, $condition) {
     
      // Updates a row into the database from key->value pairs in an array. The
      // array passed in $data must have keys for the table's columns. You can
      // not use any MySQL functions with string and date types with this
      // function.  You must use insert_sql for that purpose.
      // $condition is basically a WHERE claus (without the WHERE). For example,
      // "column=value AND column2='another value'" would be a condition.
      // Returns the number or row affected or true if no rows needed the update.
      // Returns false if there is an error.
     
      if (empty($data)) {
         $this->last_error = "You must pass an array to the update_array() function.";
         return false;
      }
     
      $sql = "UPDATE $table SET";
      foreach ($data as $key=>$value) {     // iterate values to input
         
         $sql .= " $key="; 
         
         $col_type = $this->get_column_type($table, $key);  // get column type
         if (!$col_type) return false;  // error!
         
         // determine if we need to encase the value in single quotes
         if (is_null($value)) {
            $sql .= "NULL,";   
         }
         elseif (substr_count(MYSQL_TYPES_NUMERIC, "$col_type ")) {
            $sql .= "$value,";
         }
         elseif (substr_count(MYSQL_TYPES_DATE, "$col_type ")) {
            $value = $this->sql_date_format($value, $col_type); // format date
            $sql .= "'$value',";
         }
         elseif (substr_count(MYSQL_TYPES_STRING, "$col_type ")) {
            if ($this->auto_slashes) $value = addslashes($value);
            $sql .= "'$value',"; 
         }

      }
      $sql = rtrim($sql, ','); // strip off last "extra" comma
      if (!empty($condition)) $sql .= " WHERE $condition";
     
      // insert values
      return $this->update_sql($sql);
   }
   
   function execute_file ($file) {
 
      // executes the SQL commands from an external file.
     
      if (!file_exists($file)) {
         $this->last_error = "The file $file does not exist.";
         return false;
      }
      $str = file_get_contents($file);
      if (!$str) {
         $this->last_error = "Unable to read the contents of $file.";
         return false;
      }
     
      $this->last_query = $str;
     
      // split all the query's into an array
      $sql = explode(';', $str);
      foreach ($sql as $query) {
         if (!empty($query)) {
            $r = mysql_query($query);
 
            if (!$r) {
               $this->last_error = mysql_error();
               return false;
            }
         }
      }
      return true;
   
   }
   
   function get_column_type($table, $column) {
     
      // Gets information about a particular column using the mysql_fetch_field
      // function.  Returns an array with the field info or false if there is
      // an error.
 
      $r = mysql_query("SELECT $column FROM $table");
      if (!$r) {
         $this->last_error = mysql_error();
         return false;
      }
      $ret = mysql_field_type($r, 0);
      if (!$ret) {
         $this->last_error = "Unable to get column information on $table.$column.";
         mysql_free_result($r);
         return false;
      }
      mysql_free_result($r);
      return $ret;
     
   }
   
   function sql_date_format($value) {

      // Returns the date in a format for input into the database.  You can pass
      // this function a timestamp value such as time() or a string value
      // such as '04/14/2003 5:13 AM'.
     
      if (gettype($value) == 'string') $value = strtotime($value);
      return date('Y-m-d H:i:s', $value);

   }
   function print_last_error($show_query=true) {
     
      // Prints the last error to the screen in a nicely formatted error message.
      // If $show_query is true, then the last query that was executed will
      // be displayed aswell.
 
      ?>
      <div style="border: 1px solid red; font-size: 9pt; font-family: monospace; color: red; padding: .5em; margin: 8px; background-color: #FFE2E2">
         <span style="font-weight: bold">db.class.php Error:</span><br><?= $this->last_error ?>
      </div>
      <?
      if ($show_query && (!empty($this->last_query))) {
      $this->print_last_query();
      }
 
   }

   function print_last_query() {
   
      // Prints the last query that was executed to the screen in a nicely formatted
      // box.
     
      ?>
      <div style="border: 1px solid blue; font-size: 9pt; font-family: monospace; color: blue; padding: .5em; margin: 8px; background-color: #E6E5FF">
         <span style="font-weight: bold">Last SQL Query:</span><br><?= str_replace("\n", '<br>', $this->last_query) ?>
      </div>
      <? 
   }
}

?>
 
AftershockVibe
I'd guess it doesn't like whatever you have in the $db variable. I can't remember if the new FriHost control panel does it but I seem to remember the confusion caused when creating databases in the old version. If you created a database with "Name" the real name for it would be "<username>_Name". Also, ensure that you user you are specifying has the correct access permissions.

Cool
James007
It seemed to have solved itself...

What have we learned today?

If you have a code that doesn't work, just wait.

Thank you for your input! I think it was due to the connection variables in some way.
leontius
If you are using PHP 5 you can just use PDO which is better defined and established. The thing is that hosts with PHP 4 will not have that...
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