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PHP+MySQL paging display example analysis_PHP tutorial
- WBOYOriginal
- 2016-07-13 17:32:38821browse
Web development (occupies a large proportion in current program development) will be the mainstream of distributed program development in the future, and ordinary web development (occupies a large proportion in current program development) The proportion of ) all involves dealing with the database. The client reads from the server and is usually displayed in the form of paging. Reading page by page is both convenient and beautiful. Therefore, writing paging programs is an important part of web development (which occupies a large proportion in current program development) . Here, we will study the writing of paging programs together.
1. Principle of paging program
The paging program has two very important parameters: how many records are displayed on each page ($pagesize) and what page is the current page ($page). With these two parameters, we can easily write a paging program. We use the MySQL(the best combination with PHP) database as the data source. In the MySQL(the best combination with PHP) (Best combination) If you want to retrieve a specific piece of content in the table, you can use the T-SQL statement: select * from table limit offset, rows to achieve this. The offset here is the record offset, and its calculation method is offset=$pagesize*($page-1), rows is the number of records to be displayed, here is $page. In other words, the statement select * from table limit 10,10 means to take out the 20 records starting from the 11th record in the table.
2. Main code analysis
$pagesize=10; //Set the number of records displayed on each page
$conn=MySQL(The best combination with PHP )_connect("localhost","root",""); //Connect to the database
$rs=MySQL(The best combination with PHP)_query("select count( *) from tb_product",$conn); //Get the total number of records $rs
$myrow = MySQL(The best combination with PHP)_fetch_array($rs);
$numrows =$myrow[0];
//Calculate the total number of pages
$pages=intval($numrows/$pagesize);
//Judge the page number setting
if (isset($_GET[page])){
$page=intval($_GET[page]);
}
else{
$page=1; / / Otherwise, set to the first page
}
3. Create use case table myTable
create table myTable(id int NOT NULL auto_increment, news_title varchar(50), news_cont text, add_time datetime,Prima(The most complete virtual host management system)RY KEY(id))
IV. Complete code
＜html＞
＜head＞
＜title＞php(as the current mainstream development language)Paging example＜/title＞
＜meta http-equiv="Content-Type" content="text/html; charset =gb2312"＞
＜/head＞
＜body＞
＜?php(as the current mainstream development language)
$conn=MySQL(The best combination with PHP)_connect("localhost","root","");
//Set the number of records displayed on each page
$pagesize=1;
MySQL(The best combination with PHP)_select_db("mydata",$conn);
//Get the total number of records $rs, and calculate the total number of pages with
$rs= MySQL(The best combination with PHP)_query("select count(*) from tb_product",$conn);
$myrow = MySQL(The best combination with PHP )_fetch_array($rs);
$numrows=$myrow[0];
//Calculate the total number of pages
$pages=intval($numrows/$pagesize);
if ($numrows%$pagesize)
$pages++;
//Set the number of pages
if (isset($_GET[page])){
$page=intval($_GET[ page]);
}
else{
//Set to the first page
$page=1;
}
//Calculate the record offset
$offset =$pagesize*($page - 1);
//Read the specified number of records
$rs=MySQL(The best combination with PHP)_query("select * from myTable order by id desc limit $offset,$pagesize",$conn);