php下的分頁原理學習
阿新 • • 發佈：2018-01-28
art 查詢 鏈接 ror www. 不可 生成 path count
**首先確定分頁需要確定的參數數據**
`page 當前頁碼`
`pageSize 每一頁的條數`
`total_count 總共的數據條數`
`pageNumber = ceil ( totalCount / pageSize) 總共可以分為幾頁`
begin :
**1.首先需要正確的連接數據庫查詢下總條數信息**
//配置數據庫信息
$host = "localhost:3306";
$username = "root";
$password = "";//密碼
$db = "";//表名
//創建數據庫鏈接
$conn = mysqli_connect($host, $username, $password, $db);
if (!$conn) {
echo "connect error";
exit;
}
if ($result = mysqli_query($conn, "SELECT COUNT(*) FROM 表名")) {
$row = mysqli_fetch_assoc($result);
$total_count = $row[‘COUNT(*)‘];//獲得總共的數據條數
}
php5.5 以後廢棄了之前的mysql_XXX的 api 操作 改用 mysqli_XXX的 api;
**2.判斷邊界條件生成sql語句**
`sql`語句：`"SELECT * FROM 表名 LIMIT 起始位置,數量"`
//獲得www.domain.com/xxx/xxx?page=num;url的參數
$page = $_GET[‘page‘];
//總共可分的頁數
$pageNumber = ceil($total_count / $pageSize);
if ($page <= 0 || $page > $pageNumber ) {
echo ‘404‘;//非法的page參數直接返回404
exit;
} else {
$start = ($page - 1) * 10;
}
if($result = mysqli_query($conn, "SELECT * FROM 表名 LIMIT $start,10")){
while ($row = mysqli_fetch_assoc($result)) {
echo $row[‘id‘], ‘ ‘, $row[‘name‘], "<br/>"; //查詢出結果
}
}
**3.前端分頁的顯示和url**
//邊界條件判定來確定 `上一頁` `下一頁` 按鈕的顯示和是否可以點擊； -1表示無效，即不可點擊
if ($page <= 1) {
$pre = -1;
} else {
$pre = $page - 1;
}
if ($page < $pageNumber) {
$next = $page + 1;
} else {
$next = -1;
}
$path = $_SERVER["PHP_SELF"];
if ($pre == -1) {
echo "<span class=‘pagination‘>上一頁</span>";
} else {
echo "<a class=‘pagination‘ href=‘$path?page=$pre‘>上一頁</a>";
}
if ($page == 1) {
echo "<span class=‘pagination‘>首頁</span>";
} else {
echo "<a class=‘pagination‘ href=‘$path?page=1‘>首頁</a>";
}
//分頁頁碼按鈕的顯示邏輯
// $paginationSize= 5;
//默認顯示5個連續的可點擊分頁頁碼按鈕
//頁碼數量超過一定數值後顯示前兩頁
if (($page + $paginationSize) > $next_limit) {
$end_page = $next_limit;
} else {
$end_page = $page + $paginationSize;
}
if ($page > 4) {
echo "<a class=‘pagination‘ href=‘$path?page=1‘>1</a>";
echo "<a class=‘pagination‘ href=‘$path?page=2‘>2</a>";
echo "<span class=‘point‘>···</span>";
}
for ($i = $end_page - $paginationSize; $i <= $end_page; $i++) {
if ($i == $page) {
echo "<span class=‘pagination‘>$i</span>";
} else {
echo "<a class=‘pagination‘ href=‘$path?page=$i‘>$i</a>";
}
}
if ($page == $next_limit) {
echo "<span class=‘pagination‘>尾頁</span>";
} else {
echo "<a class=‘pagination‘ href=‘$path?page=$next_limit‘>尾頁</a>";
}
if ($next == -1) {
echo "<span class=‘pagination‘ >下一頁</span>";
} else {
echo "<a class=‘pagination‘ href=‘$path?page=$next‘>下一頁</a>";
}
end:
完整代碼：
[github][1]
[1]: https://github.com/llauser/hand-demo/tree/master/php
php下的分頁原理學習