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一个简单的数据库连接和文本缓存综合类

时间：2021-07-01 10:21:17 帮助过：34人阅读

没什么特色，就是把数据库连接和文本缓存封装在一个类里面了
  1. class Db{
  2. protected $_connect;
  3. protected $_db = Array();
  4. protected $_cache = Array();
  6. public function __construct($args){
  7. list($this->_db,$this->_cache) = $args;
  8. }
  9. protected function connect($db){
  10. $this->_connect = mysql_connect($db['hostname'],$db['username'],$db['password']);
  11. mysql_set_charset('UTF8');
  12. mysql_select_db($db['databasename'],$this->_connect);
  13. }
  14. /**
  15. *作用：获取表中数据，并将所查询到的数据格式化返回，返回格式是数组形式！
  16. *$sql：传入的待执行的SQL语句，必须而且只能是SELECT
  17. *
  18. */
  19. public function fetch($sql){
  20. $result = '';
  21. if(isset($this->_cache['expire'])){
  22. $name = md5(strtolower(str_replace(' ','',$sql)));
  23. $dir = substr($name,0,2);
  24. $dir = $this->_cache['dir'].'/'.$dir;
  25. !is_dir($dir) && mkdir($dir,0777);
  26. !is_dir($dir) && mkdir($dir,0777);
  27. $this->_cache['path'] = $dir.'/'.$name;
  28. if(is_file($this->_cache['path']) && $this->check_expire()){
  29. $result = $this->get();
  30. }
  31. }
  32. if($result == ''){
  33. $data = $this->exec($sql);
  34. $result = Array();
  35. while($result[] = mysql_fetch_array($data,MYSQL_ASSOC)){} //去除索引
  36. mysql_free_result($data);
  37. array_pop($result);
  38. isset($this->_cache['expire']) && $this->write($result);
  39. }
  40. return $result;
  41. }
  42. /**
  43. *作用：执行所有的SQL语句，但不包括SELECT！
  44. *$sql：传入的待执行的SQL语句，不能为SELECT
  45. *返回值：TRUE OR FALSE
  46. */
  47. public function exec($sql){
  48. if($this->_connect === null) $this->connect($this->_db); //进行数据链接
  49. if( $result = mysql_query($sql, $this->_connect) ){
  50. return $result;
  51. }else{
  52. die("{$sql}
    执行错误: " . mysql_error());
  53. }
  54. }
  55. /**
  56. *作用：执行数据库插入语句，只能是INSERT语句！
  57. *$v：传入的待执行的条件，是数组格式table代表待执行插入的表，row是字段，value是待插入的值
  58. *返回值：mysql_insert_id() OR FALSE
  59. */
  60. public function insert($table,$field,$ignore = 0){
  61. $D = Array('field'=>'','val'=>'');
  62. foreach($field AS $key => $v){
  63. $D['field'] .= $key.',';
  64. $D['val'] .= "'{$this->escape($v)}',";
  65. }
  66. $D['field'] = rtrim($D['field'],',');
  67. $D['val'] = rtrim($D['val'],',');
  68. $ignore = $ignore > 0 ? 'IGNORE' : '';
  69. $sql = "INSERT {$ignore} INTO {$this->_db['perfix']}{$table}({$D['field']}) VALUES({$D['val']})";
  70. if($this->exec($sql)){
  71. $insert_id = mysql_insert_id();
  72. return is_numeric($insert_id) ? $insert_id : TRUE;
  73. }else{
  74. return FALSE;
  75. }
  76. }
  77. public function update($table,$field){
  78. $D = Array('where'=>'','str'=>'');
  79. $index = 0;
  80. foreach($field AS $key => $v){
  81. $index == 0 ? $D['where'] = "{$key} = '{$this->escape($v)}'" : $D['str'] .= "{$key} = '{$this->escape($v)}',";
  82. $index++;
  83. }
  84. $D['str'] = rtrim($D['str'],',');
  85. $sql = "UPDATE {$this->_db['perfix']}{$table} SET {$D['str']} WHERE {$D['where']}";
  86. return $this->exec($sql);
  88. }
  89. public function delete($table,$field){
  90. $str = '';
  91. foreach($field AS $key => $v){
  92. $str = "{$key} = '{$v}'";
  93. }
  94. $sql = 'DELETE FROM '.$this->_db['perfix'].$table.' WHERE '.$str.' LIMIT 1';
  95. return $this->exec($sql);
  96. }
  97. public function sum($table,$condition){
  98. $totle = $this->fetch('SELECT COUNT(*) AS totle FROM '.$this->_db['perfix'].$table.' WHERE '.$condition);
  99. return $totle[0]['totle'];
  100. }
  101. /**
  102. *作用：对输入特殊字符进行过滤
  103. *$v：待传入检测的参数
  104. *返回值：检测完的参数
  105. */
  106. public function escape($v){
  107. return mysql_real_escape_string($v);
  108. }
  109. /*
  110. *作用：进行缓存判断
  111. */
  112. public function cache($name,$expire=100000000){
  113. $this->_cache['expire'] = $expire;
  114. return $this;
  115. }
  116. public function check_expire(){
  117. return (filemtime($this->_cache['path']) + $this->_cache['expire']) > strtotime("now");
  118. }
  120. public function write($data){
  121. $f = fopen($this->_cache['path'], 'w');
  122. if ($f) {
  123. flock($f, LOCK_EX);
  124. fseek($f, 0);
  125. ftruncate($f, 0);
  126. $tmp = fwrite($f, serialize($data));
  127. if (!($tmp === false)) {
  128. $result = true;
  129. }
  130. fclose($f);
  131. }
  132. chmod($this->_cache['path'],0777);
  133. }
  134. public function get(){
  135. $f = fopen($this->_cache['path'], 'r');
  136. $data = fread($f,filesize($this->_cache['path']));
  137. fclose($f);
  138. return unserialize($data);
  139. }
  140. public function delete_dir($dir = ''){
  141. $dir = empty($dir) ? $this->_cache['dir'] : $dir;
  142. !is_dir($dir) && exit;
  143. $d = opendir($dir);
  144. $i = 0;
  145. while(($file = readdir($d)) !== false){
  146. $path = $dir.'/'.$file;
  147. if($i > 1) is_file($path) ? unlink($path) : $this->delete_dir($path);
  148. $i++;
  149. }
  150. closedir($d);
  151. rmdir($dir);
  152. }
  153. public function __destruct(){
  154. isset($this->_connect) && mysql_close($this->_connect);
  155. }
  156. }

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