在分頁中使用“下一步”和“上一頁”

Question

我正在使用以下代碼段。 下一個按鈕可以正常工作，但是當顯示所有結果並且沒有更多內容顯示時，下一個按鈕仍會顯示。 這是我正在使用的：

  //check if the starting row variable was passed in the URL or not
 if (!isset($_GET['pg']) or !is_numeric($_GET['pg'])) {
//we give the value of the starting row to 0 because nothing was found in URL
  $startrow = 0;
 //otherwise we take the value from the URL
  } else {
 $startrow = (int)mysql_real_escape_string($_GET['pg']);
}



 if($num_rows > 10) {
 echo 'next';
 } 

 $prev = $startrow - 10;

 //only print a "Previous" link if a "Next" was clicked
if ($prev >= 0) {
echo 'previous';

 }

Answer 1

要確定是否要顯示下一個按鈕，您必須知道頁面總數，並將其與當前頁面索引進行比較。

$itemPerPage = 10;
$firstPage = 0; // or 1, depending on your implementation
$totalPage = ceil($num_rows / $itemPerPage);
$currentPage = (int)$_GET['pg'];
if($currentPage > $firstPage)
   echo 'prev';

if($currentPage < $totalPage)
   echo 'next';

在您的情況下，請確保您不會在頁面和項目編號之間弄亂，因為頁面可能會顯示許多項目。

Answer 2

嘗試這樣的事情：

<?php
// database connection info
$conn = mysql_connect('localhost','dbusername','dbpass') or trigger_error("SQL", E_USER_ERROR);
$db = mysql_select_db('dbname',$conn) or trigger_error("SQL", E_USER_ERROR);

// find out how many rows are in the table 
$sql = "SELECT COUNT(*) FROM numbers";
$result = mysql_query($sql, $conn) or trigger_error("SQL", E_USER_ERROR);
$r = mysql_fetch_row($result);
$numrows = $r[0];

// number of rows to show per page
$rowsperpage = 10;
// find out total pages
$totalpages = ceil($numrows / $rowsperpage);

// get the current page or set a default
if (isset($_GET['currentpage']) && is_numeric($_GET['currentpage'])) {
   // cast var as int
   $currentpage = (int) $_GET['currentpage'];
} else {
   // default page num
   $currentpage = 1;
} // end if

// if current page is greater than total pages...
if ($currentpage > $totalpages) {
   // set current page to last page
   $currentpage = $totalpages;
} // end if
// if current page is less than first page...
if ($currentpage < 1) {
   // set current page to first page
   $currentpage = 1;
} // end if

// the offset of the list, based on current page 
$offset = ($currentpage - 1) * $rowsperpage;

// get the info from the db 
$sql = "SELECT id, number FROM numbers LIMIT $offset, $rowsperpage";
$result = mysql_query($sql, $conn) or trigger_error("SQL", E_USER_ERROR);

// while there are rows to be fetched...
while ($list = mysql_fetch_assoc($result)) {
   // echo data
   echo $list['id'] . " : " . $list['number'] . "<br />";
} // end while

/******  build the pagination links ******/
// range of num links to show
$range = 3;

// if not on page 1, don't show back links
if ($currentpage > 1) {
   // show << link to go back to page 1
   echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=1'><<</a> ";
   // get previous page num
   $prevpage = $currentpage - 1;
   // show < link to go back to 1 page
   echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$prevpage'><</a> ";
} // end if 

// loop to show links to range of pages around current page
for ($x = ($currentpage - $range); $x < (($currentpage + $range) + 1); $x++) {
   // if it's a valid page number...
   if (($x > 0) && ($x <= $totalpages)) {
      // if we're on current page...
      if ($x == $currentpage) {
         // 'highlight' it but don't make a link
         echo " [<b>$x</b>] ";
      // if not current page...
      } else {
         // make it a link
   echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$x'>$x</a> ";
      } // end else
   } // end if 
} // end for

// if not on last page, show forward and last page links    
if ($currentpage != $totalpages) {
   // get next page
   $nextpage = $currentpage + 1;
    // echo forward link for next page 
   echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$nextpage'>></a> ";
   // echo forward link for lastpage
   echo " <a href='{$_SERVER['PHP_SELF']}?currentpage=$totalpages'>>></a> ";
} // end if
/****** end build pagination links ******/
?>

Answer 3

考慮到您提出這個問題的次數，我強烈建議您學習 PHP分頁。

PHP Freaks有一個不錯的教程。

如何使用PHP分頁數據真的打破了它並構建了一個類。

基本的PHP和MySQL分頁教程是相當標准的。

搜索詞組“php mysql分頁教程”有19萬條 Google搜索結果

玩得開心，祝你好運！

Answer 4

也許這個php分頁類可能對你有用

問候。