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zg/class.db.php

Created Jul 22, 2011
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db class
<?php
/*********************************************************************
* Database Abstraction Layer
**********************************************************************
* Related Files:
* --------------------------------------------------------------
**********************************************************************
* Revision History:
* --------------------------------------------------------------
*********************************************************************/
/*********************************************************************
* Constants
*********************************************************************/
define('OBJECT','OBJECT',true);
define('ARRAY_A','ARRAY_A',true);
define('ARRAY_N','ARRAY_N',true);
class db {
/**********************************************************************
* Properties
**********************************************************************/
var $dbuser = '';
var $dbpassword = '';
var $dbname = '';
var $dbhost = '';
var $trace = false; // same as $debug_all
var $debug_all = false; // same as $trace
var $debug_echo_is_on = false;
var $show_errors = false;
var $debug_called = false;
var $vardump_called = false;
var $last_error = null;
var $captured_errors = array();
var $num_queries = 0;
var $last_query = null;
var $col_info = null;
var $cache_dir = '/srv/http/us/4ch/sidetrack/cache';
var $cache_queries = false;
var $cache_inserts = false;
var $use_disk_cache = false;
var $cache_timeout = 4; // hours
var $error_labels = array
(
1 => '$dbuser and $dbpassword are required to connect to a database server',
2 => '$dbname is required to select a database',
3 => 'Error establishing database connection',
4 => 'Database connection is not active',
5 => 'Unexpected error while trying to select database'
);
/**********************************************************************
* Constructor - Allow quick set of connection properties
* during instantiation
**********************************************************************/
function __construct($dbuser='', $dbpassword='', $dbname='', $dbhost='')
{
//use default connection params unless they are supplied
if (!empty($dbuser) || !empty($dbpassword) || !empty($dbname) || !empty($dbhost))
{
$this->dbuser = $dbuser;
$this->dbpassword = $dbpassword;
$this->dbname = $dbname;
$this->dbhost = $dbhost;
}
}
/**********************************************************************
* Connect to database server and select a database
**********************************************************************/
function connect()
{
$return_val = false;
// Must have a user and a password
if (empty($this->dbuser) || empty($this->dbpassword))
{
$this->register_error($this->error_labels[1].' in '.__FILE__.' on line '.__LINE__);
$this->show_errors ? trigger_error($this->error_labels[1],E_USER_WARNING) : null;
}
// Try to establish the server database handle
else if (!$this->dbh = mysql_connect($this->dbhost,$this->dbuser,$this->dbpassword,true))
{
$this->register_error($this->error_labels[3].' in '.__FILE__.' on line '.__LINE__);
$this->show_errors ? trigger_error($this->error_labels[3],E_USER_WARNING) : null;
}
// Connected. Now select the database
else
{
$return_val = true;
!empty($this->dbname) ? $this->select($this->dbname) : null;
}
mysql_query('SET NAMES utf8',$this->dbh); //utf8 on all connections
return $return_val;
}
/**********************************************************************
* Select a database
**********************************************************************/
function select()
{
$return_val = false;
// Must have a database name
if (empty($this->dbname))
{
$this->register_error($this->error_labels[3].' in '.__FILE__.' on line '.__LINE__);
$this->show_errors ? trigger_error($this->error_labels[3],E_USER_WARNING) : null;
}
// Must have an active database connection
else if (!$this->dbh)
{
$this->register_error($this->error_labels[4].' in '.__FILE__.' on line '.__LINE__);
$this->show_errors ? trigger_error($this->error_labels[4],E_USER_WARNING) : null;
}
// Try to connect to the database
else if (!mysql_select_db($this->dbname,$this->dbh))
{
// Try to get error supplied by mysql if not use our own
if (!$str = mysql_error($this->dbh))
{
$str = $this->error_labels[5];
}
$this->register_error($str.' in '.__FILE__.' on line '.__LINE__);
$this->show_errors ? trigger_error($str,E_USER_WARNING) : null;
}
else
{
$return_val = true;
}
return $return_val;
}
/**********************************************************************
* Perform SQL query and try to determine result value
**********************************************************************/
function query($query)
{
// Initialise return
$return_val = 0;
// Flush cached values
$this->flush();
// For reg expressions
$query = trim($query);
// Log how the function was called
$this->func_call = "\$db->query(\"$query\")";
// Keep track of the last query for debug
$this->last_query = $query;
// Count how many queries there have been
$this->num_queries++;
// Use cache
if ($cache = $this->get_cache($query))
{
return $cache;
}
// If there is no existing database connection then try to connect
if (!isset($this->dbh) || !$this->dbh)
{
$this->connect();
}
$query = preg_replace('/SELECT /i', 'SELECT SQL_CALC_FOUND_ROWS ',$query,1);
// Perform the query via std mysql_query function..
$this->result = mysql_query($query,$this->dbh);
// If there is an error then take note of it..
if ($str = mysql_error($this->dbh))
{
$this->register_error($str);
$this->show_errors ? trigger_error($str,E_USER_WARNING) : null;
return false;
}
// Query was an insert, delete, update, replace
$is_insert = false;
if ( preg_match("/^(insert|delete|update|replace)\s+/i",$query) )
{
$this->rows_affected = mysql_affected_rows();
// Take note of the insert_id
if ( preg_match("/^(insert|replace)\s+/i",$query) )
{
$this->insert_id = mysql_insert_id($this->dbh);
}
// Return number of rows affected
$return_val = true;
}
// Query was a select
else
{
// Take note of column info
$i=0;
while ($i < mysql_num_fields($this->result))
{
$this->col_info[$i] = mysql_fetch_field($this->result);
$i++;
}
// Store Query Results
$num_rows=0;
while ($row = mysql_fetch_object($this->result))
{
// Store relults as an objects within main array
$this->last_result[$num_rows] = $row;
$num_rows++;
}
mysql_free_result($this->result);
// Log number of rows the query returned
$this->num_rows = $num_rows;
// Log found number of rows (avoids the LIMIT clause)
$found_rows_sql = mysql_query('SELECT FOUND_ROWS()');
$found_rows = mysql_fetch_assoc($found_rows_sql);
$this->found_rows = $found_rows['FOUND_ROWS()'];
// Return number of rows selected
$return_val = $this->num_rows;
}
// disk caching of queries
$this->store_cache($query,$is_insert);
// If debug ALL queries
$this->trace || $this->debug_all ? $this->debug() : null;
return $return_val;
}
/**********************************************************************
* Return a single row
* @param int $y - row offset
**********************************************************************/
function get_row($query=null,$output=OBJECT,$y=0)
{
// Log how the function was called
$this->func_call = "\$db->get_row(\"$query\",$output,$y)";
// If there is a query then perform it if not then use cached results..
if ( $query )
{
$this->query($query);
}
// If the output is an object then return object using the row offset..
if ( $output == OBJECT )
{
return $this->last_result[$y]?$this->last_result[$y]:null;
}
// If the output is an associative array then return row as such..
elseif ( $output == ARRAY_A )
{
return $this->last_result[$y]?get_object_vars($this->last_result[$y]):null;
}
// If the output is an numerical array then return row as such..
elseif ( $output == ARRAY_N )
{
return $this->last_result[$y]?array_values(get_object_vars($this->last_result[$y])):null;
}
// If invalid output type was specified..
else
{
$str = "\$db->get_row(string query, output type, int offset) -- Output type must be one of: OBJECT, ARRAY_A, ARRAY_N";
$this->register_error($str);
$this->show_errors ? trigger_error($str,E_USER_WARNING) : null;
}
}
/**********************************************************************
* Return the the query as a result set
**********************************************************************/
function get_results($query=null, $output = OBJECT)
{
// Log how the function was called
$this->func_call = "\$db->get_results(\"$query\", $output)";
// If there is a query then perform it if not then use cached results..
if ($query)
{
$this->query($query);
}
// Send back array of objects. Each row is an object
if ( $output == OBJECT )
{
return $this->last_result;
}
elseif ( $output == ARRAY_A || $output == ARRAY_N )
{
if ( $this->last_result )
{
$i=0;
foreach( $this->last_result as $row )
{
$new_array[$i] = get_object_vars($row);
if ( $output == ARRAY_N )
{
$new_array[$i] = array_values($new_array[$i]);
}
$i++;
}
return $new_array;
}
else
{
return null;
}
}
}
/**********************************************************************
* Function to get column meta data info pertaining to the last query
**********************************************************************/
function get_col_info($info_type="name",$col_offset=-1)
{
if ( $this->col_info )
{
if ( $col_offset == -1 )
{
$i=0;
foreach($this->col_info as $col )
{
$new_array[$i] = $col->{$info_type};
$i++;
}
return $new_array;
}
else
{
return $this->col_info[$col_offset]->{$info_type};
}
}
}
/**********************************************************************
* Kill cached query results
**********************************************************************/
function flush()
{
// Get rid of these
$this->last_result = null;
$this->col_info = null;
$this->last_query = null;
$this->from_disk_cache = false;
}
/**********************************************************************
* Cache the query
**********************************************************************/
function store_cache($query,$is_insert)
{
// The would be cache file for this query
$cache_file = $this->cache_dir . md5($query);
// disk caching of queries
if ( $this->use_disk_cache && ( $this->cache_queries && ! $is_insert ) || ( $this->cache_inserts && $is_insert ))
{
if (!is_dir($this->cache_dir))
{
$this->register_error("Could not open cache dir: $this->cache_dir");
$this->show_errors ? trigger_error("Could not open cache dir: $this->cache_dir",E_USER_WARNING) : null;
}
else
{
// Cache all result values
$result_cache = array
(
'col_info' => $this->col_info,
'last_result' => $this->last_result,
'num_rows' => $this->num_rows,
'return_value' => $this->num_rows,
);
error_log(serialize($result_cache), 3, $cache_file);
}
}
}
/**********************************************************************
* Get cached query
**********************************************************************/
function get_cache($query)
{
// The would be cache file for this query
$cache_file = $this->cache_dir . md5($query);
// Try to get previously cached version
if ( $this->use_disk_cache && file_exists($cache_file) )
{
// Only use this cache file if less than 'cache_timeout' (hours)
if ((time() - filemtime($cache_file)) > ($this->cache_timeout*3600))
{
unlink($cache_file);
}
else
{
$result_cache = unserialize(file_get_contents($cache_file));
$this->col_info = $result_cache['col_info'];
$this->last_result = $result_cache['last_result'];
$this->num_rows = $result_cache['num_rows'];
$this->from_disk_cache = true;
// If debug ALL queries
$this->trace || $this->debug_all ? $this->debug() : null ;
return $result_cache['return_value'];
}
}
}
/**********************************************************************
* Register SQL/DB error
**********************************************************************/
function register_error($err_str)
{
// Keep track of last error
$this->last_error = $err_str;
// Capture all errors to an error array no matter what happens
$this->captured_errors[] = array
(
'error_str' => $err_str,
'query' => $this->last_query
);
}
/**********************************************************************
* Dumps the contents of any input variable to screen in a nicely
* formatted and easy to understand way - any data type
**********************************************************************/
function vardump($mixed='')
{
// Start outup buffering
ob_start();
echo "<p><table><tr><td bgcolor='ffffff'><blockquote style='margin-top: 1em; margin-right: 0px; margin-bottom: 1em; margin-left: 40px;'><font color='000090'>";
echo "<pre><font>";
if (!$this->vardump_called)
{
echo "<font color='800080'><b>DAO: Variable Dump</b></font>\n\n";
}
$var_type = gettype ($mixed);
print_r(($mixed?$mixed:"<font color='red'>No Value / False</font>"));
echo "\n\n<b>Type:</b> " . ucfirst($var_type) . "\n";
echo "<b>Last Query [$this->num_queries]:</b> ".($this->last_query?$this->last_query:"NULL")."\n";
echo "<b>Last Function Call:</b> " . ($this->func_call?$this->func_call:"None")."\n";
echo "<b>Last Rows Returned:</b> ".count($this->last_result)."\n";
echo "</font></pre></font></blockquote></td></tr></table>";
echo "\n<hr size='1' noshade color='dddddd'>";
// Stop output buffering and capture debug HTML
$html = ob_get_contents();
ob_end_clean();
// Only echo output if it is turned on
if ( $this->debug_echo_is_on )
{
echo $html;
}
$this->vardump_called = true;
return $html;
}
/**********************************************************************
* Displays the last query string that was sent to the database and
* a table listing results (if there were any).
**********************************************************************/
function debug()
{
// Start output buffering
ob_start();
echo "<blockquote style='margin-top: 1em; margin-right: 0px; margin-bottom: 1em; margin-left: 40px;'>";
// Only show heading once
if ( ! $this->debug_called )
{
echo "<font color='800080' size='2'><b>DAO: debug()</b></font><p>\n";
}
if ( $this->last_error )
{
echo "<font size='2' color='000099'><b>Last Error --</b> [<font color='000000'><b>$this->last_error</b></font>]<p>";
}
if ( $this->from_disk_cache )
{
echo "<font size='2' color='000099'><b>Results retrieved from disk cache</b></font><p>";
}
echo "<font size='2' color='000099'><b>Query</b> [$this->num_queries] <b>--</b> ";
echo "[<font color='000000'><b>$this->last_query</b></font>]</font><p>";
echo "<font size='2' color='000099'><b>Query Result..</b></font>";
echo "<blockquote style='margin-top: 1em; margin-right: 0px; margin-bottom: 1em; margin-left: 40px;'>";
if ( $this->col_info )
{
// =====================================================
// Results top rows
echo "<table cellpadding='5' cellspacing='1' bgcolor='555555'>";
echo "<tr bgcolor='eeeeee'><td nowrap valign='bottom'><font color='555599' size='2'><b>(row)</b></font></td>";
for ( $i=0; $i < count($this->col_info); $i++ )
{
echo "<td nowrap align='left' valign='top'><font size='1' color='555599'>{$this->col_info[$i]->type} {$this->col_info[$i]->max_length}</font><br><span style='font-size: 10pt; font-weight: bold;'>{$this->col_info[$i]->name}</span></td>";
}
echo "</tr>";
// ======================================================
// print main results
if ( $this->last_result )
{
$i=0;
foreach ( $this->get_results(null,ARRAY_N) as $one_row )
{
$i++;
echo "<tr bgcolor='ffffff'><td bgcolor='eeeeee' nowrap align='middle'><font size='2' color='555599'>$i</font></td>";
foreach ( $one_row as $item )
{
echo "<td nowrap><font size='2'>$item</font></td>";
}
echo "</tr>";
}
} // if last result
else
{
echo "<tr bgcolor='ffffff'><td colspan=".(count($this->col_info)+1)."><font size='2'>No Results</font></td></tr>";
}
echo "</table>";
} // if col_info
else
{
echo "<font size='2'>No Results</font>";
}
// Stop output buffering and capture debug HTML
$html = ob_get_contents();
ob_end_clean();
// Only echo output if it is turned on
if ( $this->debug_echo_is_on )
{
echo $html;
}
$this->debug_called = true;
return $html;
}
/**********************************************************************
* Format a SQL string correctly for safe SQL insert
**********************************************************************/
function escape($str)
{
return mysql_escape_string(stripslashes($str));
}
/**********************************************************************
* Return mySQL specific system date syntax
**********************************************************************/
function sysdate()
{
return 'NOW()';
}
}
?>
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