PHP入门

下面给大家看看我的数据库结构吧：数据库的名字为：fa_category

     我们使用一个parentid字段来记录父节点的id，如果parentid为0，则为root。不多说，我们看看代码怎么写吧。我们要实现的功能就是如图片所示：

简单的mysql数据表结构

CREATE TABLE messages
(
msg_id INT PRIMARY KEY AUTO_INCREMENT,
message VARCHAR(150)
);

<?php
// Adam's Custom PHP MySQL Pagination Tutorial and Script
// You have to put your mysql connection data and alter the SQL queries(both queries)
// This script is in tutorial form and is accompanied by the following video:
mysql_connect("DB_Host_Here","DB_Username_Here","DB_Password_Here") or die (mysql_error());
mysql_select_db("DB_Name_Here") or die (mysql_error());
//////////////  QUERY THE MEMBER DATA INITIALLY LIKE YOU NORMALLY WOULD
$sql = mysql_query("SELECT id, firstname, country FROM myTable ORDER BY id ASC");
//////////////////////////////////// Adam's Pagination Logic ////////////////////////////////////////////////////////////////////////
$nr = mysql_num_rows($sql); // Get total of Num rows from the database query
if (isset($_GET['pn'])) { // Get pn from URL vars if it is present
    $pn = preg_replace('#[^0-9]#i', '', $_GET['pn']); // filter everything but numbers for security(new)
    //$pn = ereg_replace("[^0-9]", "", $_GET['pn']); // filter everything but numbers for security(deprecated)
} else { // If the pn URL variable is not present force it to be value of page number 1
    $pn = 1;
}
//This is where we set how many database items to show on each page
$itemsPerPage = 10;
// Get the value of the last page in the pagination result set
$lastPage = ceil($nr / $itemsPerPage);
// Be sure URL variable $pn(page number) is no lower than page 1 and no higher than $lastpage
if ($pn < 1) { // If it is less than 1
    $pn = 1; // force if to be 1
} else if ($pn > $lastPage) { // if it is greater than $lastpage
    $pn = $lastPage; // force it to be $lastpage's value
}
// This creates the numbers to click in between the next and back buttons
// This section is explained well in the video that accompanies this script
$centerPages = "";
$sub1 = $pn - 1;
$sub2 = $pn - 2;
$add1 = $pn + 1;
$add2 = $pn + 2;
if ($pn == 1) {
    $centerPages .= '&nbsp; <span class="pagNumActive">' . $pn . '</span> &nbsp;';
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $add1 . '">' . $add1 . '</a> &nbsp;';
} else if ($pn == $lastPage) {
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $sub1 . '">' . $sub1 . '</a> &nbsp;';
    $centerPages .= '&nbsp; <span class="pagNumActive">' . $pn . '</span> &nbsp;';
} else if ($pn > 2 && $pn < ($lastPage - 1)) {
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $sub2 . '">' . $sub2 . '</a> &nbsp;';
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $sub1 . '">' . $sub1 . '</a> &nbsp;';
    $centerPages .= '&nbsp; <span class="pagNumActive">' . $pn . '</span> &nbsp;';
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $add1 . '">' . $add1 . '</a> &nbsp;';
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $add2 . '">' . $add2 . '</a> &nbsp;';
} else if ($pn > 1 && $pn < $lastPage) {
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $sub1 . '">' . $sub1 . '</a> &nbsp;';
    $centerPages .= '&nbsp; <span class="pagNumActive">' . $pn . '</span> &nbsp;';
    $centerPages .= '&nbsp; <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $add1 . '">' . $add1 . '</a> &nbsp;';
}
// This line sets the "LIMIT" range... the 2 values we place to choose a range of rows from database in our query
$limit = 'LIMIT ' .($pn - 1) * $itemsPerPage .',' .$itemsPerPage;
// Now we are going to run the same query as above but this time add $limit onto the end of the SQL syntax
// $sql2 is what we will use to fuel our while loop statement below
$sql2 = mysql_query("SELECT id, firstname, country FROM myTable ORDER BY id ASC $limit");
//////////////////////////////// END Adam's Pagination Logic ////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////// Adam's Pagination Display Setup /////////////////////////////////////////////////////////////////////
$paginationDisplay = ""; // Initialize the pagination output variable
// This code runs only if the last page variable is ot equal to 1, if it is only 1 page we require no paginated links to display
if ($lastPage != "1"){
    // This shows the user what page they are on, and the total number of pages
    $paginationDisplay .= 'Page <strong>' . $pn . '</strong> of ' . $lastPage. '&nbsp;  &nbsp;  &nbsp; ';
    // If we are not on page 1 we can place the Back button
    if ($pn != 1) {
        $previous = $pn - 1;
        $paginationDisplay .=  '&nbsp;  <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $previous . '"> Back</a> ';
    }
    // Lay in the clickable numbers display here between the Back and Next links
    $paginationDisplay .= '<span class="paginationNumbers">' . $centerPages . '</span>';
    // If we are not on the very last page we can place the Next button
    if ($pn != $lastPage) {
        $nextPage = $pn + 1;
        $paginationDisplay .=  '&nbsp;  <a href="' . $_SERVER['PHP_SELF'] . '?pn=' . $nextPage . '"> Next</a> ';
    }
}
///////////////////////////////////// END Adam's Pagination Display Setup ///////////////////////////////////////////////////////////////////////////
// Build the Output Section Here
$outputList = '';
while($row = mysql_fetch_array($sql2)){

三种方法.

1.

//计算数组的合并 array_merge与“+”的区别
array_merge() 函数把两个或多个数组合并为一个数组。

如果键名有重复，该键的键值为最后一个键名对应的值（后面的覆盖前面的）。如果数组是数字索引的，则键名会以连续方式重新索引。

一维数组

第一组 ：sort 和 rsort ，按照PHP数组键值的顺序asc和逆序desc进行排序，同时破坏原来数组的索引关系——其实是删除索引之后重新建立从0开始的数字索引。看一下例程：

、登录时对用户输入的用户名、密码进行验证

<?php

核心代码

<script type="text/javascript">
 
$(document).ready(function() {
 
    $("#login").click(function() {
 
        var action = $("#form1").attr('action');
 
        var form_data = {
 
            username: $("#username").val(),
 
            password: $("#password").val(),
 
            is_ajax: 1
 
        };
 
        $.ajax({
 
            type: "POST",
 
            url: action,
 
            data: form_data,
 
            success: function(response)
 
            {
 
                if(response == 'success')
 
                    $("#form1").slideUp('slow', function() {
 
                        $("#message").html("<p class='success'>登陆成功!</p>");
 
                    });
 
                else
 
                    $("#message").html("<p class='error'>用户名或密码错误.</p>");   
 
            }
 
        });
 
        return false;
 
    });
 
});
 
</script>

请记住从PHP文件创建的教训，我们创建了一个文件，名为testFile.txt 。

$myFile = "testFile.txt";
$fh = fopen($myFile, 'w') or die("can't open file");
fclose($fh);
判断是否删除了.

例

<?php
/* php foreach循环简单例子 */   
$a = array('a'=>'网上','b'=>'朋友','c'=>'其它',);   
// 这是一个hash数组,我们现在把内容输出   
foreach ($a as $key => $value) {   
    echo $key . '->' . $value . '<br>';   
}   
?>  
<?php
$a = array('a'=>'网上','b'=>'朋友','c'=>'其它',);

先来看ob_start用法

使用PHP ob_start()函数打开browser的cache，这样可以保证cache的内容在你调用flush(),ob_end_flush()（或程序执行完毕）之前不会被输出

<?

// Start snipit 1