php pdo自动分页类代码与例子

2. /**
3. * 类名: PdoPage
4. * 作者：谢声涛 [e-mail]
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 // 计算总记录数
27. $rs = @parent::query($this->rebuildSqlString($SqlString));
28. $this->Rows = $rs->fetchColumn();
29. // 计算总页数
30. if ($this->Rows PageSize) {$this->Pages = 1;}
31. elseif ($this->Rows % $this->PageSize) {$this->Pages = intval($this->Rows/$this->PageSize)+1;}
32. else {$this->Pages = intval($this->Rows/$this->PageSize);}
33. // 约束CurrentPage值，使之位于1到Pages之间。
34. if($this->CurrentPage CurrentPage =1;}
35. if($this->CurrentPage > $this->Pages) {$this->CurrentPage = $this->Pages;}
36. //计算偏移量
37. $Offset = $this->PageSize * ($this->CurrentPage - 1);
38. // 重组SQL语句,SqlString有分号则去掉
39. $SqlString = str_replace(";","",$SqlString) . " LIMIT $Offset,$this->PageSize;";
40. }
41. // 查询并返回记录集
42. $rs = new PDOStatement();
43. $rs = @parent::query($SqlString);
44. $this->RecordSet = $rs->fetchAll();//returns an array.
45. $this->RecordCount = count($this->RecordSet);
46. if(!$this->AutoPage){$this->Pages = (!$this->RecordCount)?0:1;}
47. return $this->RecordCount;
48. }
49. // 取得字段值
50. public function FieldValue($FieldName=""){
51. return ($this->RecordSet[$this->mCurrentRow][$FieldName]);
52. }
53. //--------移动记录集游标---------------
54. public function Move($RowPos){
55. if ($RowPosif ($RowPos > $this->RecordCount-1) $RowPos = $this->RecordCount-1;
56. $this->mCurrentRow = $RowPos;
57. $this->EOF = false;
58. $this->BOF = false;
59. }
60. public function MoveNext(){
61. if($this->mCurrentRow RecordCount-1){
62. $this->mCurrentRow++;
63. $this->EOF = false;
64. $this->BOF = false;
65. }
66. else{
67. $this->EOF = true;
68. }
69. }
70. public function MovePrev(){
71. if($this->mCurrentRow > 0){
72. $this->mCurrentRow--;
73. $this->EOF = false;
74. $this->BOF = false;
75. }else{
76. $this->BOF = true;
77. }
78. }
79. public function MoveFirst(){
80. $this->mCurrentRow = 0;
81. $this->EOF = false;
82. $this->BOF = false;
83. }
84. public function MoveLast(){
85. $this->mCurrentRow = $this->RecordCount-1;
86. $this->EOF = false;
87. $this->BOF = false;
88. }
89. //--------------------------------------------------
90. // 用于执行插入、修改、删除等操作
91. public function Execute($SqlString){
92. return @parent::query($SqlString);
93. }
94. //-----------------私有函数-----------------------------
95. // 重新构造SQL语句，如将"select * from tb2"改写为"select count(*) from tb2"，旨在提高查询效率。
96. private function rebuildSqlString($SqlString){
97. if(preg_match("/select[ ,./w+/*]+ from/",$SqlString,$marr)){
98. $columns = preg_replace("/select|from/","",$marr[0]);
99. $columns = preg_replace("//*/","/*",$columns);
100. $result = preg_replace("/$columns/"," count(*) ",$SqlString);
101. return $result;
102. }
103. }
104. //-------------结束-----------------------------------
105. }
106. //-------------结束-----------------------------------
107. ?>

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2、使用示例： 需修改MySQL用户名、密码、数据库名等信息。

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

17. ?>

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