这篇文章主要介绍了SESSION存放在数据库用法,自定义了一个简单的针对数据操作的session类并给出了使用该类存储到数据库的相关技巧,需要的朋友可以参考下

本文实例讲述了SESSION存放在数据库用法，分享给大家供大家参考，具体如下：

1. <?php
2. /*
3. CREATE TABLE `ws_sessions` (
4. `session_id` varchar(255) binary NOT NULL default '',
5. `session_expires` int(10) unsigned NOT NULL default '0',
6. `session_data` text,
7. PRIMARY KEY (`session_id`)
8. ) TYPE=InnoDB;
9. */
10. class session {
11. // session-lifetime
12. var $lifeTime;
13. // mysql-handle
14. var $dbHandle;
15. function open($savePath, $sessName) {
16. // get session-lifetime
17. $this->lifeTime = get_cfg_var("session.gc_maxlifetime");
18. // open database-connection
19. $dbHandle = @mysql_connect("localhost","root","");
20. $dbSel = @mysql_select_db("test",$dbHandle);
21. // return success
22. if(!$dbHandle || !$dbSel)
23. return false;
24. $this->dbHandle = $dbHandle;
25. return true;
26. }
27. function close() {
28. $this->gc(ini_get('session.gc_maxlifetime'));
29. // close database-connection
30. return @mysql_close($this->dbHandle);
31. }
32. function read($sessID) {
33. // fetch session-data
34. $res = mysql_query("SELECT session_data AS d FROM ws_sessions
35. WHERE session_id = '$sessID'
36. AND session_expires > ".time(),$this->dbHandle);
37. // return data or an empty string at failure
38. if($row = mysql_fetch_assoc($res))
39. return $row['d'];
40. return "";
41. }
42. function write($sessID,$sessData) {
43. // new session-expire-time
44. $newExp = time() + $this->lifeTime;
45. // is a session with this id in the database?
46. $res = mysql_query("SELECT * FROM ws_sessions
47. WHERE session_id = '$sessID'",$this->dbHandle);
48. // if yes,
49. if(mysql_num_rows($res)) {
50. // ...update session-data
51. mysql_query("UPDATE ws_sessions
52. SET session_expires = '$newExp',
53. session_data = '$sessData'
54. WHERE session_id = '$sessID'",$this->dbHandle);
55. // if something happened, return true
56. if(mysql_affected_rows($this->dbHandle))
57. return true;
58. }
59. // if no session-data was found,
60. else {
61. // create a new row
62. mysql_query("INSERT INTO ws_sessions (
63. session_id,
64. session_expires,
65. session_data)
66. VALUES(
67. '$sessID',
68. '$newExp',
69. '$sessData')",$this->dbHandle);
70. // if row was created, return true
71. if(mysql_affected_rows($this->dbHandle))
72. return true;
73. }
74. // an unknown error occured
75. return false;
76. }
77. function destroy($sessID) {
78. // delete session-data
79. mysql_query("DELETE FROM ws_sessions WHERE session_id = '$sessID'",$this->dbHandle);
80. // if session was deleted, return true,
81. if(mysql_affected_rows($this->dbHandle))
82. return true;
83. // ...else return false
84. return false;
85. }
86. function gc($sessMaxLifeTime) {
87. // delete old sessions
88. mysql_query("DELETE FROM ws_sessions WHERE session_expires < ".time(),$this->dbHandle);
89. // return affected rows
90. return mysql_affected_rows($this->dbHandle);
91. }
92. }
93. $session = new session();
94. session_set_save_handler(array(&$session,"open"),
95. array(&$session,"close"),
96. array(&$session,"read"),
97. array(&$session,"write"),
98. array(&$session,"destroy"),
99. array(&$session,"gc"));
100. session_start();
101. // etc...
102. ?>

希望本文所述对大家的php程序设计有所帮助。