Php provides the paging function in three ways: Page 1/3, page 3 _ PHP Tutorial

Php provides three paging methods: 13th pages and 3 pages. Php implements the paging function in three ways: 13th pages, and code is directly displayed on three pages. I hope you can read it carefully. Method 1: When Querying SQL queries by page, you need to call several functions. for details, see page 1/3 in three ways of implementing the paging function in php. page 3

I hope you can read the code carefully.

Method 1: SQL query is performed by page. several functions need to be called. for details, see the script:
1. pager. class. php

<? Php class pager {public $ SQL; // SQL query statement public $ datanum; // query the total number of data records. public $ page_size; // The number of records displayed on each page. protected $ _ errstr; protected $ _ conn; protected $ _ query_id; public function query ($ query) // This function is faulty, you do not need to use {$ ret = false; if (! Empty ($ query) {if ($ this-> _ conn = false |! Is_resource ($ this-> _ conn) {warningLog (_ METHOD __. ': query SQL with no connection', true); return false;} $ this-> _ query_id = @ mysql_query ($ query, $ this-> _ conn ); if ($ this-> _ query_id === false) {$ this-> _ errstr = @ mysql_error (); $ ret = false ;} else {$ this-> _ errstr = 'success'; $ ret = $ this-> _ query_id; }}$ msg = ($ ret = false )? 'False': strval ($ ret); debugLog (_ METHOD __. ": [$ msg] returned for SQL query [$ query]"); return $ ret;} function _ construct ($ SQL, $ page_size) {$ result = mysql_query ($ SQL); $ datanum = mysql_num_rows ($ result); $ this-> SQL = $ SQL; $ this-> datanum = $ datanum; $ this-> page_size = $ page_size;} // public function page_id () {if ($ _ SERVER ['query _ string'] = "") of the current page "") {return 1;} elseif (substr_count ($ _ SERVER ['query _ S TRING '], "page_id =") = 0) {return 1;} else {return intval (substr ($ _ SERVER ['query _ string'], 8) ;}} // remaining url value public function url () {if ($ _ SERVER ['query _ string'] = "") {return "";} elseif (substr_count ($ _ SERVER ['query _ string'], "page_id =") = 0) {return "&". $ _ SERVER ['query _ string'];} else {return str_replace ("page_id = ". $ this-> page_id (), "", $ _ SERVER ['query _ string']) ;}// total page number public function page_num () {If ($ this-> datanum = 0) {return 1;} else {return ceil ($ this-> datanum/$ this-> page_size );}} // offset of database query public function start () {return ($ this-> page_id ()-1) * $ this-> page_size ;} // data output public function sqlquery () {return $ this-> SQL. "limit ". $ this-> start (). ",". $ this-> page_size;} // get the current file name private function php_self () {return $ _ SERVER ['php _ SELF '];} // the previous private function pre_page () {if ($ this -> Page_id () = 1) {// The number of pages equals 1 return "php_self ()."? Page_id = 1 ". $ this-> url ()."> Previous Page ";} elseif ($ this-> page_id ()! = 1) {// The number of pages is not equal to 1 return "php_self ()."? Page_id = ". ($ this-> page_id ()-1 ). $ this-> url (). "> Previous Page" ;}}// display the private function display_page () {$ display_page = ""; if ($ this-> page_num () <= 10) {// page less than 10 for ($ I = 1; $ I <= $ this-> page_num (); $ I ++) // The page is displayed cyclically $ display_page. = "php_self (). "? Page_id = ". $ I. $ this-> url (). "> ". $ I. ""; return $ display_page;} elseif ($ this-> page_num ()> 10) {// if ($ this-> page_id () <= 6) {for ($ I = 1; $ I <= 10; $ I ++) // The page is displayed cyclically $ display_page. = "php_self (). "? Page_id = ". $ I. $ this-> url (). "> ". $ I. ""; return $ display_page;} elseif ($ this-> page_id ()> 6) & ($ this-> page_num ()-$ this-> page_id ()> = 4) {for ($ I = $ this-> page_id ()-5; $ I <= $ this-> page_id () + 4; $ I ++) // The Page $ display_page is displayed cyclically. = "php_self (). "? Page_id = ". $ I. $ this-> url (). "> ". $ I. ""; return $ display_page;} elseif ($ this-> page_id ()> 6) & ($ this-> page_num ()-$ this-> page_id () <4) {for ($ I = $ this-> page_num ()-9; $ I <= $ this-> page_num (); $ I ++) // The Page $ display_page is displayed cyclically. = "php_self (). "? Page_id = ". $ I. $ this-> url (). "> ". $ I. ""; return $ display_page ;}}// next page private function next_page () {if ($ this-> page_id () <$ this-> page_num ()) {// The number of pages is smaller than the total number of pages return "php_self (). "? Page_id = ". ($ this-> page_id () + 1 ). $ this-> url (). "> Next Page";} elseif ($ this-> page_id () = $ this-> page_num () {// The number of pages equals to the total number of pages return "php_self (). "? Page_id = ". $ this-> page_num (). $ this-> url (). "> Next Page" ;}}// set the page information public function set_page_info () {$ page_info = "total ". $ this-> datanum. "entries"; $ page_info. = "php_self (). "? Page_id = 1 ". $ this-> url (). "> homepage"; $ page_info. = $ this-> pre_page (); $ page_info. = $ this-> display_page (); $ page_info. = $ this-> next_page (); $ page_info. = "php_self (). "? Page_id = ". $ this-> page_num (). $ this-> url (). "> last page"; $ page_info. = "th ". $ this-> page_id (). "/". $ this-> page_num (). "page"; return $ page_info ;}}?>

2. Script 2:

<? Php // class usage // read paging class include ("pager. class. php "); // database connection initialization // $ db = new mysql (); $ impeach_host = '10. 81.43.139 '; $ impeach_usr = 'vmtest15'; $ region = 'vmtest15'; $ impeach_name = 'ufeature'; $ impeach_con = mysql_connect ($ impeach_host, $ impeach_usr, $ region) or die ("Can't connect ". mysql_error (); mysql_select_db ($ impeach_name, $ impeach_con); // This is an SQL query statement and gets the query result $ SQL = "select word from ufeature. spam_accuse_word_list where flag = '0' "; // page initialization $ page = new pager ($ SQL, 20 ); // 20 is the number displayed per page // $ res_1 = mysql_query ($ SQL) or // die ("Can't get result ". mysql_error (); $ result = mysql_query ($ page-> sqlquery (); while ($ info = mysql_fetch_array ($ result, MYSQL_ASSOC )) {// while ($ info = mysql_fetch_array ($ res_1, MYSQL_ASSOC) {echo $ info ["word"]."
";}// Page number index echo $ page-> set_page_info () ;?>

Method 2: ajax
1. First, understand the limit usage in SQL statements.

SELECT * FROM table ...... Limit start position, number of operations (where the start position starts from 0)

Example
Take the first 20 records: SELECT * FROM table ...... Limit 0, 20
Obtain 20 records FROM 11th: SELECT * FROM table ...... Limit 10, 20
LIMIT n is equivalent to LIMIT 0, n.
For exampleSelect * from table LIMIT 5; // return the first five rows,AndSelect * from table LIMIT 0, 5Same
2. paging principle
The so-called paging display, that is, the result set in the database, is displayed in a segment
How to segment, the current segment (the number of lines per page, and the number of pages next)
The first 10 records:Select * from table limit 0, 10
11th to 20 records:Select * from table limit 10, 10
21st to 30 records:Select * from table limit 20, 10
Paging formula:
(Current page-1) X number of entries per page, number of entries per page

Select * from table limit ($Page- 1) * $PageSize, $PageSize 

3. $ _ SERVER ["REQUEST_URI"] function
A type of predefined SERVER variables. all variables starting with $ _ SERVER are called SERVER variables.
REQUEST_URI is used to obtain the current URI, which is the complete address path after the domain name.
Example:
The current page is: http://www.test.com/home.php? Id = 23 & cid = 22
Echo $ _ SERVER ["REQUEST_URI"]
Result:/home. php? Id = 23 & cid = 22
4. parse_url () parses the URL function.
Parse_url () is a function that parses a URL into an array with a fixed key value.
Example

$ua=parse_url("http://username:password@hostname/path?arg=value#anchor");print_r($ua);

Result:

Array ([scheme] => http; protocol [host] => hostname; host domain name [user] => username; user [pass] => password; password [path] =>/path; path [query] => arg = value; parameter [fragment] => anchor ;)

5. code example
The page for this message is divided into three parts: database design, connection page, and display page.
(1) design a database
The database name is bbs. there is a data table named message, which contains the title, lastdate, user, content and other fields, indicating the message title, message date, message recipient, and message content.
(2) connection page

<? Php $ conn = @ mysql_connect ("localhost", "root", "123456") or die ("database link error"); mysql_select_db ("bbs", $ conn ); mysql_query ("set names 'gbk'"); // uses GBK Chinese encoding; // converts spaces and line breaks to HTML-resolvable function htmtocode ($ content) {$ content = str_replace ("\ n ","
", Str_replace (" "," ", $ content); // Two str_replace nested return $ content;} // $ content = str_replace ("'","'", $ content); // htmlspecialchars ();?>

(3) display page

<? Php include ("conn. php "); $ pagesize = 2; // set to display 2 records on each page $ url = $ _ SERVER [" REQUEST_URI "]; $ url = parse_url ($ url ); $ url = $ url [path]; $ numq = mysql_query ("SELECT * FROM 'message'"); $ num = mysql_num_rows ($ numq); if ($ _ GET
Pipeline directly uploads the code. I hope you can read it carefully. Method 1: SQL query is performed by page. several functions need to be called. for details, see...