增删改查是对数据库最基本的操作，下面详细为大家介绍下如何连接数据库以及增删改查等等相关知识。

　　1.链接数据库通用方法：conn.php

　　代码如下:

<?php
//第一步：链接数据库
$conn=@mysql_connect("localhost:3306","root","root")or die ("mysql链接失败");
//第二步: 选择指定的数据库，设置字符集
@mysql_select_db("php_blog",$conn) or die ("db链接失败".mysql_error());
mysql_query('SET NAMES UTF8')or die ("字符集设置错误");
?>

　　2.增加 add.php

　　代码如下:

<?php
include("conn.php");//引入链接数据库
if(!empty($_POST['sub'])){
$title=$_POST['title'];
$con=$_POST['con'];
echo $sql="insert into news(id,title,dates,contents) value (null,'$title',now(),'$con')" ;
mysql_query($sql);
echo"插入成功";
}
?>
<form action="add.php" method="post">
标题: <input type="text" name="title"><br>
内容: <textarea rows="5" cols="50" name="con"></textarea><br>
<input type="submit" name="sub" value="发表">
</form>

　　3.删除del.php

　　代码如下:

<?php
include("conn.php");//引入链接数据库<pre name="code" class="html"><?php
include("conn.php");//引入链接数据库
if(!empty ($_GET['id'])){
$sql="select * from news where id='".$_GET['id']."'";
$query=mysql_query($sql);
$rs=mysql_fetch_array($query);
}
if(!empty($_POST['sub'])){
$title=$_POST['title'];
$con=$_POST['con'];
$hid=$_POST['hid'];
$sql="update news set title='$title',contents='$con' where id='$hid' limit 1 ";
mysql_query($sql);
echo "<script> alert('更新成功'); location.href='index.php'</script>";
echo"更新成功";
}
?>
<form action="edit.php" method="post">
<input type="hidden" name="hid" value="<?php echo $rs['id']?>"/>
标题: <input type="text" name="title" value="<?php echo $rs['title']?>"><br>
内容: <textarea rows="5" cols="50" name="con"><?php echo $rs['contents']?></textarea><br>
<input type="submit" name="sub" value="发表">
</form></pre><br>
if(!empty($_GET['del'])){ $d=$_GET['del']; $sql="delete from news where id ='$d'"; } $query=mysql_query($sql); echo "删除成功"; ?><p></p>
<pre></pre>
<br>

　　4，改 edit.php页面

<p></p>
<p><br>
</p>
<p></p><pre name="code" class="html"><?php
include("conn.php");//引入链接数据库
if(!empty ($_GET['id'])){
$sql="select * from news where id='".$_GET['id']."'";
$query=mysql_query($sql);
$rs=mysql_fetch_array($query);
}
if(!empty($_POST['sub'])){
$title=$_POST['title'];
$con=$_POST['con'];
$hid=$_POST['hid'];
$sql="update news set title='$title',contents='$con' where id='$hid' limit 1 ";
mysql_query($sql);
echo "<script> alert('更新成功'); location.href='index.php'</script>";
echo"更新成功";
}
?>
<form action="edit.php" method="post">
<input type="hidden" name="hid" value="<?php echo $rs['id']?>"/>
标题: <input type="text" name="title" value="<?php echo $rs['title']?>"><br>
内容: <textarea rows="5" cols="50" name="con"><?php echo $rs['contents']?></textarea><br>
<input type="submit" name="sub" value="发表">
</form></pre><br>

　　5.查，列表页面<pre name="code" class="html"><a href="add.php">添加内容</a>
<hr>
<hr>
<form>
<input type="text" name="keys" />
<input type="submit" name="subs" value="搜索"/>
</form>
<?php
include("conn.php");//引入链接数据库
if(!empty($_GET['keys'])){
$w=" title like '%".$_GET['keys']."%'";
}else{
$w=1;
}
$sql="select * from news where $w order by id desc";
$query=mysql_query($sql);
while($rs=mysql_fetch_array($query)){
?>
<h2>标题:<a href="view.php?id=<?php echo $rs['id'] ?>"><?php echo $rs['title'] ?></a> <a href="edit.php?id=<?php echo $rs['id'] ?>">编辑</a>｜｜<a href="del.php?del=<?php echo $rs['id'] ?>">删除</a></h2>
<li><?php echo $rs['dates'] ?></li>
<p><?php echo $rs['contents'] ?></p>
<hr>
<?php
}
?>
</pre><br>
<p></p>
<p><br>
</p>