<?
  /** A PHP class to access MySQL database with convenient methods
    * in an object oriented way, and with a powerful debug system.\n
    * Licence:  LGPL \n
    * Web site: http://slaout.linux62.org/
    * @version  1.0
    * @author   S&eacute;bastien Lao&ucirc;t (slaout@linux62.org)
    */
  class DB
  {
    /** Put this variable to true if you want ALL queries to be debugged by default:
      */
    var $defaultDebug = false;

    /** INTERNAL: The start time, in miliseconds.
      */
    var $mtStart;
    /** INTERNAL: The number of executed queries.
      */
    var $nbQueries;
    /** INTERNAL: The last result ressource of a query().
      */
    var $lastResult;

    /** Connect to a MySQL database to be able to use the methods below.
      */
    function DB($base, $server, $user, $pass)
    {
      $this->mtStart    = $this->getMicroTime();
      $this->nbQueries  = 0;
      $this->lastResult = NULL;
      mysql_connect($server, $user, $pass) or die('Server connexion not possible.');
      mysql_select_db($base)               or die('Database connexion not possible.');
    }

    /** Query the database.
      * @param $query The query.
      * @param $debug If true, it output the query and the resulting table.
      * @return The result of the query, to use with fetchNextObject().
      */
    function query($query, $debug = -1)
    {
      $this->nbQueries++;
      $this->lastResult = mysql_query($query) or $this->debugAndDie($query);

      $this->debug($debug, $query, $this->lastResult);

      return $this->lastResult;
    }
    /** Do the same as query() but do not return nor store result.\n
      * Should be used for INSERT, UPDATE, DELETE...
      * @param $query The query.
      * @param $debug If true, it output the query and the resulting table.
      */
    function execute($query, $debug = -1)
    {
      $this->nbQueries++;
      mysql_query($query) or $this->debugAndDie($query);

      $this->debug($debug, $query);
    }
    /** Convenient method for mysql_fetch_object().
      * @param $result The ressource returned by query(). If NULL, the last result returned by query() will be used.
      * @return An object representing a data row.
      */
    function fetchNextObject($result = NULL)
    {
      if ($result == NULL)
        $result = $this->lastResult;

      if ($result == NULL || mysql_num_rows($result) < 1)
        return NULL;
      else
        return mysql_fetch_object($result);
    }
    /** Get the number of rows of a query.
      * @param $result The ressource returned by query(). If NULL, the last result returned by query() will be used.
      * @return The number of rows of the query (0 or more).
      */
    function numRows($result = NULL)
    {
      if ($result == NULL)
        return mysql_num_rows($this->lastResult);
      else
        return mysql_num_rows($result);
    }
    /** Get the result of the query as an object. The query should return a unique row.\n
      * Note: no need to add "LIMIT 1" at the end of your query because
      * the method will add that (for optimisation purpose).
      * @param $query The query.
      * @param $debug If true, it output the query and the resulting row.
      * @return An object representing a data row (or NULL if result is empty).
      */
    function queryUniqueObject($query, $debug = -1)
    {
      $query = "$query LIMIT 1";

      $this->nbQueries++;
      $result = mysql_query($query) or $this->debugAndDie($query);

      $this->debug($debug, $query, $result);

      return mysql_fetch_object($result);
    }
    /** Get the result of the query as value. The query should return a unique cell.\n
      * Note: no need to add "LIMIT 1" at the end of your query because
      * the method will add that (for optimisation purpose).
      * @param $query The query.
      * @param $debug If true, it output the query and the resulting value.
      * @return A value representing a data cell (or NULL if result is empty).
      */
    function queryUniqueValue($query, $debug = -1)
    {
      $query = "$query LIMIT 1";

      $this->nbQueries++;
      $result = mysql_query($query) or $this->debugAndDie($query);
      $line = mysql_fetch_row($result);

      $this->debug($debug, $query, $result);

      return $line[0];
    }
    /** Get the maximum value of a column in a table, with a condition.
      * @param $column The column where to compute the maximum.
      * @param $table The table where to compute the maximum.
      * @param $where The condition before to compute the maximum.
      * @return The maximum value (or NULL if result is empty).
      */
    function maxOf($column, $table, $where)
    {
      return $this->queryUniqueValue("SELECT MAX(`$column`) FROM `$table` WHERE $where");
    }
    /** Get the maximum value of a column in a table.
      * @param $column The column where to compute the maximum.
      * @param $table The table where to compute the maximum.
      * @return The maximum value (or NULL if result is empty).
      */
    function maxOfAll($column, $table)
    {
      return $this->queryUniqueValue("SELECT MAX(`$column`) FROM `$table`");
    }
    /** Get the count of rows in a table, with a condition.
      * @param $table The table where to compute the number of rows.
      * @param $where The condition before to compute the number or rows.
      * @return The number of rows (0 or more).
      */
    function countOf($table, $where)
    {
      return $this->queryUniqueValue("SELECT COUNT(*) FROM `$table` WHERE $where");
    }
    /** Get the count of rows in a table.
      * @param $table The table where to compute the number of rows.
      * @return The number of rows (0 or more).
      */
    function countOfAll($table)
    {
      return $this->queryUniqueValue("SELECT COUNT(*) FROM `$table`");
    }
    /** Internal function to debug when MySQL encountered an error,
      * even if debug is set to Off.
      * @param $query The SQL query to echo before diying.
      */
    function debugAndDie($query)
    {
      $this->debugQuery($query, "Error");
      die("<p style=\"margin: 2px;\">".mysql_error()."</p></div>");
    }
    /** Internal function to debug a MySQL query.\n
      * Show the query and output the resulting table if not NULL.
      * @param $debug The parameter passed to query() functions. Can be boolean or -1 (default).
      * @param $query The SQL query to debug.
      * @param $result The resulting table of the query, if available.
      */
    function debug($debug, $query, $result = NULL)
    {
      if ($debug === -1 && $this->defaultDebug === false)
        return;
      if ($debug === false)
        return;

      $reason = ($debug === -1 ? "Default Debug" : "Debug");
      $this->debugQuery($query, $reason);
      if ($result == NULL)
        echo "<p style=\"margin: 2px;\">Number of affected rows: ".mysql_affected_rows()."</p></div>";
      else
        $this->debugResult($result);
    }
    /** Internal function to output a query for debug purpose.\n
      * Should be followed by a call to debugResult() or an echo of "</div>".
      * @param $query The SQL query to debug.
      * @param $reason The reason why this function is called: "Default Debug", "Debug" or "Error".
      */
    function debugQuery($query, $reason = "Debug")
    {
      $color = ($reason == "Error" ? "red" : "orange");
      echo "<div style=\"border: solid $color 1px; margin: 2px;\">".
           "<p style=\"margin: 0 0 2px 0; padding: 0; background-color: #DDF;\">".
           "<strong style=\"padding: 0 3px; background-color: $color; color: white;\">$reason:</strong> ".
           "<span style=\"font-family: monospace;\">".htmlentities($query)."</span></p>";
    }
    /** Internal function to output a table representing the result of a query, for debug purpose.\n
      * Should be preceded by a call to debugQuery().
      * @param $result The resulting table of the query.
      */
    function debugResult($result)
    {
      echo "<table border=\"1\" style=\"margin: 2px;\">".
           "<thead style=\"font-size: 80%\">";
      $numFields = mysql_num_fields($result);
      // BEGIN HEADER
      $tables    = array();
      $nbTables  = -1;
      $lastTable = "";
      $fields    = array();
      $nbFields  = -1;
      while ($column = mysql_fetch_field($result)) {
        if ($column->table != $lastTable) {
          $nbTables++;
          $tables[$nbTables] = array("name" => $column->table, "count" => 1);
        } else
          $tables[$nbTables]["count"]++;
        $lastTable = $column->table;
        $nbFields++;
        $fields[$nbFields] = $column->name;
      }
      for ($i = 0; $i <= $nbTables; $i++)
        echo "<th colspan=".$tables[$i]["count"].">".$tables[$i]["name"]."</th>";
      echo "</thead>";
      echo "<thead style=\"font-size: 80%\">";
      for ($i = 0; $i <= $nbFields; $i++)
        echo "<th>".$fields[$i]."</th>";
      echo "</thead>";
      // END HEADER
      while ($row = mysql_fetch_array($result)) {
        echo "<tr>";
        for ($i = 0; $i < $numFields; $i++)
          echo "<td>".htmlentities($row[$i])."</td>";
        echo "</tr>";
      }
      echo "</table></div>";
      $this->resetFetch($result);
    }
    /** Get how many time the script took from the begin of this object.
      * @return The script execution time in seconds since the
      * creation of this object.
      */
    function getExecTime()
    {
      return round(($this->getMicroTime() - $this->mtStart) * 1000) / 1000;
    }
    /** Get the number of queries executed from the begin of this object.
      * @return The number of queries executed on the database server since the
      * creation of this object.
      */
    function getQueriesCount()
    {
      return $this->nbQueries;
    }
    /** Go back to the first element of the result line.
      * @param $result The resssource returned by a query() function.
      */
    function resetFetch($result)
    {
      if (mysql_num_rows($result) > 0)
        mysql_data_seek($result, 0);
    }
    /** Get the id of the very last inserted row.
      * @return The id of the very last inserted row (in any table).
      */
    function lastInsertedId()
    {
      return mysql_insert_id();
    }
    /** Close the connexion with the database server.\n
      * It's usually unneeded since PHP do it automatically at script end.
      */
    function close()
    {
      mysql_close();
    }

    /** Internal method to get the current time.
      * @return The current time in seconds with microseconds (in float format).
      */
    function getMicroTime()
    {
      list($msec, $sec) = explode(' ', microtime());
      return floor($sec / 1000) + $msec;
    }
  } // class DB
?>