phppdo自动分页类代码与例子

2. /**
3. * 类名: PdoPage
4. * 作者：谢声涛 shishengsoft@gmail.com
5. * 描述: 继承自PDO类，增加了自动分页功能，类似MS ADO组件的自动分页功能。
6. */ bbs.it-home.org
7. //-------------开始---------------
8. class PdoPage extends PDO {
9. public $RecordCount = 0; // 记录集的记录总数
10. public $AutoPage = false;// 启用自动分页功能
11. public $PageSize = 0;// 每页的记录行数
12. public $CurrentPage = 0; // 当前页
13. public $Pages = 0;// 总页数
14. public $BOF = false; // 游标到记录集之前
15. public $EOF = false; // 游标到记录集之后
16. private $RecordSet = null; // 记录集
17. private $mCurrentRow = -1; // 记录集中当前游标位置
18. private $Rows = 0;//总记录数
19. // 关闭连接
20. public function Close(){unset($this);}
21. // 分页查询
22. public function QueryEx($SqlString){
23. // 是否启用自动分页功能
24. if($this->AutoPage){
25. // 检查PageSize参数
26. if ($this->PageSize <=0) die("警告：PageSize不能为负数或零。");
27. // 计算总记录数
28. $rs = @parent::query($this->rebuildSqlString($SqlString));
29. $this->Rows = $rs->fetchColumn();
30. // 计算总页数
31. if ($this->Rows < $this->PageSize) {$this->Pages = 1;}
32. elseif ($this->Rows % $this->PageSize) {$this->Pages = intval($this->Rows/$this->PageSize)+1;}
33. else {$this->Pages = intval($this->Rows/$this->PageSize);}
34. // 约束CurrentPage值，使之位于1到Pages之间。
35. if($this->CurrentPage < 1) {$this->CurrentPage =1;}
36. if($this->CurrentPage > $this->Pages) {$this->CurrentPage = $this->Pages;}
37. //计算偏移量
38. $Offset = $this->PageSize * ($this->CurrentPage - 1);
39. // 重组SQL语句,SqlString有分号则去掉
40. $SqlString = str_replace(";","",$SqlString) . " LIMIT $Offset,$this->PageSize;";
41. }
42. // 查询并返回记录集
43. $rs = new PDOStatement();
44. $rs = @parent::query($SqlString);
45. $this->RecordSet = $rs->fetchAll();//returns an array.
46. $this->RecordCount = count($this->RecordSet);
47. if(!$this->AutoPage){$this->Pages = (!$this->RecordCount)?0:1;}
48. return $this->RecordCount;
49. }
50. // 取得字段值
51. public function FieldValue($FieldName=""){
52. return ($this->RecordSet[$this->mCurrentRow][$FieldName]);
53. }
54. //--------移动记录集游标---------------
55. public function Move($RowPos){
56. if ($RowPos<0) $RowPos = 0;
57. if ($RowPos > $this->RecordCount-1) $RowPos = $this->RecordCount-1;
58. $this->mCurrentRow = $RowPos;
59. $this->EOF = false;
60. $this->BOF = false;
61. }
62. public function MoveNext(){
63. if($this->mCurrentRow < $this->RecordCount-1){
64. $this->mCurrentRow++;
65. $this->EOF = false;
66. $this->BOF = false;
67. }
68. else{
69. $this->EOF = true;
70. }
71. }
72. public function MovePrev(){
73. if($this->mCurrentRow > 0){
74. $this->mCurrentRow--;
75. $this->EOF = false;
76. $this->BOF = false;
77. }else{
78. $this->BOF = true;
79. }
80. }
81. public function MoveFirst(){
82. $this->mCurrentRow = 0;
83. $this->EOF = false;
84. $this->BOF = false;
85. }
86. public function MoveLast(){
87. $this->mCurrentRow = $this->RecordCount-1;
88. $this->EOF = false;
89. $this->BOF = false;
90. }
91. //--------------------------------------------------
92. // 用于执行插入、修改、删除等操作
93. public function Execute($SqlString){
94. return @parent::query($SqlString);
95. }
96. //-----------------私有函数-----------------------------
97. // 重新构造SQL语句，如将"select * from tb2"改写为"select count(*) from tb2"，旨在提高查询效率。
98. private function rebuildSqlString($SqlString){
99. if(preg_match("/select[ ,./w+/*]+ from/",$SqlString,$marr)){
100. $columns = preg_replace("/select|from/","",$marr[0]);
101. $columns = preg_replace("//*/","/*",$columns);
102. $result = preg_replace("/$columns/"," count(*) ",$SqlString);
103. return $result;
104. }
105. }
106. //-------------结束-----------------------------------
107. }
108. //-------------结束-----------------------------------
109. ?>

2、使用示例： 需修改MySQL用户名、密码、数据库名等信息。

3. include_once("./pdopage_class.php");

4. $db = new PdoPage("mysql:host=localhost;dbname=mydb","root","123456");
5. $db->Execute("set character set gbk;");
6. $db->AutoPage = false;
7. $db->PageSize = 6;
8. $db->CurrentPage = 1;
9. $db->QueryEx("select * from tb2;");
10. $db->MoveFirst();
11. while (!$db->EOF) {
12. echo $db->FieldValue("id"),"/t",$db->FieldValue("name"),"/t",$db->FieldValue("age"),"/n";
13. $db->MoveNext();
14. }
15. $db->Close();

16. ?>