一个php调用数据库的类

3. class DataBase

4. {
5. var $pConnect=FALSE;//是否使用长连接
6. var $mHost;//数据库主机
7. var $mDatabase;
8. var $db; //数据库
9. var $mUser;//数据库用户名
10. var $mPwd;//数据库用户密码
11. var $mConn;//连接标识
12. var $result;// 执行query命令的结果资源标识
13. var $num_rows;// 返回的条目数
14. var $insert_id;// 传回最后一次使用 INSERT 指令的 ID
15. var $affected_rows;// 传回query命令所影响的列数目
16. // INSERT、UPDATE 或 DELETE 所影响的列 (row) 数目。
17. // delete 如果不带where，那么则返回0
18. //构造函数
19. public function __construct($host,$user,$pwd,$db)
20. {
21. $this->mHost=$host;
22. $this->mUser=$user;
23. $this->mPwd=$pwd;
24. $this->db=$db;
25. }
27. //数据库连接
28. public function connect()
29. {
30. if($this->pConnect)
31. $this->mConn=mysql_pconnect($this->mHost,$this->mUser,$this->mPwd);//长连接
32. else
33. $this->mConn=mysql_connect($this->mHost,$this->mUser,$this->mPwd);//short connect

34. if(!$this->mConn) $this->dbhalt("不能连接数据库!");

35. if($this->db=="") $this->db=$this->dbDatabase;
37. if(!mysql_select_db($this->db,$this->mConn))
38. $this->dbhalt("数据库不可用!");
39. } // eof#dbconnect()

40. //更改数据库

41. public function dbChange($db){
42. $this->db=$db;
43. $this->connect();
44. }

45. //执行SQL语句,返回结果资源id

46. public function execute($sql){
47. $this->result=mysql_query($sql);
48. return $this->result;
49. }

50. //获取数组-索引和关联

51. public function fetchArray($resultType=MYSQL_BOTH)
52. {
53. return mysql_fetch_array($this->result,$resultType);
54. }
56. //获取关联数组
57. public function fetchAssoc()
58. {
59. return mysql_fetch_assoc($this->result);
60. }
62. //获取数字索引数组
63. public function fetchIndexArray()
64. {
65. return mysql_fetch_row($this->result);
66. }
68. //获取对象数组
69. public function fetchObject()
70. {
71. return mysql_fetch_object($this->result);
72. }
74. //返回记录行数
75. function numRows()
76. {
77. return mysql_num_rows($this->result);
78. }

79. //返回主机中所有数据库名

80. public function dbNames()
81. {
82. $rsPtr=mysql_list_dbs($this->mConn);
83. $i=0;
84. $cnt=mysql_num_rows($rsPtr);
85. while($i<$cnt)
86. {
87. $rs[]=mysql_db_name($rsPtr,$i);
88. $i++;
89. }
90. return $rs;
91. }

92. function dbhalt($errmsg){

93. $msg="数据库有问题!";
94. $msg=$errmsg;
95. echo"$msg";
96. die();
97. }

98. //删

99. function delete($sql){
100. $result=$this->execute($sql,$dbbase);
101. $this->affected_rows=mysql_affected_rows($this->dbLink);
102. $this->free_result($result);
103. return $this->affected_rows;
104. }

105. //增

106. function insert($sql){
107. $result=$this->execute($sql,$dbbase);
108. $this->insert_id=mysql_insert_id($this->dbLink);
109. $this->free_result($result);
110. return $this->insert_id;
111. }

112. //改

113. function update($sql){
114. $result=$this->execute($sql,$dbbase);
115. $this->affected_rows=mysql_affected_rows($this->dbLink);
116. $this->free_result($result);
117. return $this->affected_rows;
118. }
120. //关闭连接
121. function dbclose(){
122. mysql_close($this->dbLink);
123. }
124. }// end class
125. ?>

调用示例：

3. include "class_database.php";

4. $mydb=new DataBase("localhost","root","123456","test");

5. $mydb->connect();
6. $mydb->execute("set names GBK");
7. $mydb->execute("select * from usrs");
8. print_r($mydb->dbNames());
9. ?>