我可以列出数据库记录,但我无法更新记录(MYSQL,XAMPP,PHP)

I don't know the problem whether it is about my.ini. Can somebody can help me?? I can list the record, but i cannot update the record.

list_property.php

<title>List Property</title>
</head>

<?php

// Connect to server and select database.
mysql_connect("localhost", "root", "123456")or die("cannot connect"); 
mysql_select_db("album")or die("cannot select DB");


$sql="SELECT * FROM property";
$result=mysql_query($sql);

?>
<body>


<table width="1200" border="1" cellspacing="1" cellpadding="0">
<tr>
<td>
<table width="1200" border="1" cellspacing="1" cellpadding="3">
<tr>
<td colspan="50"><strong>List the property</strong> </td>
</tr>

<tr>
<td align="center"><strong>Update_date</strong></td>
<td align="center"><strong>Usage</strong></td>
<td align="center"><strong>Region</strong></td>
<td align="center"><strong>Street</strong></td>
<td align="center"><strong>Building</strong></td>
<td align="center"><strong>Layers</strong></td>
<td align="center"><strong>Unit</strong></td>
<td align="center"><strong>Construction_area</strong></td>
<td align="center"><strong>Saleable_area</strong></td>
<td align="center"><strong>Price</strong></td>
<td align="center"><strong>Rent</strong></td>
<td align="center"><strong>Contant_person</strong></td>
<td align="center"><strong>Contant_Num</strong></td>
<td align="center"><strong>Layout</strong></td>
<td align="center"><strong>Decoration</strong></td>
</tr>

<?php
while($rows=mysql_fetch_array($result)){
?>
<tr>
<td><?php echo $rows['Update_date']; ?></td>
<td><?php echo $rows['Usage']; ?></td>
<td><?php echo $rows['Region']; ?></td>
<td><?php echo $rows['Street']; ?></td> 
<td><?php echo $rows['Building']; ?></td>
<td><?php echo $rows['Layers']; ?></td>
<td><?php echo $rows['Unit']; ?></td>
<td><?php echo $rows['Construction_area']; ?></td> 
<td><?php echo $rows['Saleable_area']; ?></td>
<td><?php echo $rows['Price']; ?></td>
<td><?php echo $rows['Rent']; ?></td>
<td><?php echo $rows['Contant_person']; ?></td> 
<td><?php echo $rows['Contant_Num']; ?></td>
<td><?php echo $rows['Layout']; ?></td>
<td><?php echo $rows['Decoration']; ?></td>
<td align="center"><a href="update.php?P_ID=<?php echo $rows['P_ID']; ?>">update</a></td>
</tr>

<?php
}
?>

</table>
</td>
</tr>
</table>
</body>
</html>

update.php

<title>Update Property</title>
</head>

<?php
// Connect to server and select database.
mysql_connect("localhost", "root", "123456")or die("cannot connect"); 
mysql_select_db("album") or die("cannot select DB");

// get value of id that sent from address bar
$P_ID=$_GET['P_ID'];



// Retrieve data from database 
$sql="SELECT * FROM album.property WHERE P_ID = '$P_ID'";
$result=mysql_query($sql);
$rows=mysql_fetch_array($result);
?>
<body>


<table width="1200" border="0" cellspacing="1" cellpadding="0">
<tr>
<form name="form1" method="post" action="update_ac.php">
<td>
<table width="100%" border="0" cellspacing="1" cellpadding="0">
<tr>
<td>&nbsp;</td>
<td colspan="6"><strong>Update Property Details</strong> </td>
</tr>
<tr>
<td align="center">&nbsp;</td>
<td align="center">&nbsp;</td>
<td align="center">&nbsp;</td>
<td align="center">&nbsp;</td>
<td align="center">&nbsp;</td>
<td align="center">&nbsp;</td>
<td align="center">&nbsp;</td>
<td align="center">&nbsp;</td>
<td align="center">&nbsp;</td>
<td align="center">&nbsp;</td>
<td align="center">&nbsp;</td>
<td align="center">&nbsp;</td>
<td align="center">&nbsp;</td>
<td align="center">&nbsp;</td>
</tr>
<tr>
<td align="center">&nbsp;</td>
<td align="center"><strong>Usage</strong></td>
<td align="center"><strong>Region</strong></td>
<td align="center"><strong>Street</strong></td>
<td align="center"><strong>Building</strong></td>
<td align="center"><strong>Layers</strong></td>
<td align="center"><strong>Unit</strong></td>
<td align="center"><strong>Construction_area</strong></td>
<td align="center"><strong>Saleable_area</strong></td>
<td align="center"><strong>Price</strong></td>
<td align="center"><strong>Rent</strong></td>
<td align="center"><strong>Contant_person</strong></td>
<td align="center"><strong>Contant_Num</strong></td>
<td align="center"><strong>Layout</strong></td>
<td align="center"><strong>Decoration</strong></td>
</tr>
<tr>
<td>&nbsp;</td>
<td align="center">
<input name="Usage" type="text" P_ID="Usage" value="<?php echo $rows['Usage']; ?>"size= "15"/>
</td>
<td align="center">
<input name="Region" type="text" P_ID="Region" value="<?php echo $rows['Region']; ?>" size="15"/>
</td>
<td align="center">
<input name="Street" type="text" P_ID="Street" value="<?php echo $rows['Street']; ?>" size="15"/>
</td>
<td align="center">
<input name="Building" type="text" P_ID="Building" value="<?php echo $rows['Building']; ?>" size="15"/>
</td>
<td align="center">
<input name="Layers" type="text" P_ID="Layers" value="<?php echo $rows['Layers']; ?>" size="15"/>
</td>
<td align="center">
<input name="Unit" type="text" P_ID="Unit" value="<?php echo $rows['Unit']; ?>" size="15"/>
</td>
<td align="center">
<input name="Construction_area" type="text" P_ID="Construction_area" value="<?php echo $rows['Construction_area']; ?>" size="15"/>
</td>
<td align="center">
<input name="Saleable_area" type="text" P_ID="Saleable_area" value="<?php echo $rows['Saleable_area']; ?>" size="15"/>
</td>
<td align="center">
<input name="Price" type="text" P_ID="Price" value="<?php echo $rows['Price']; ?>" size="15"/>
</td>
<td align="center">
<input name="Rent" type="text" P_ID="Rent" value="<?php echo $rows['Rent']; ?>" size="15"/>
</td>
<td align="center">
<input name="Contant_person" type="text" P_ID="Contant_person" value="<?php echo $rows['Contant_person']; ?>" size="15"/>
</td>
<td align="center">
<input name="Contant_Num" type="text" P_ID="Contant_Num" value="<?php echo $rows['Contant_Num']; ?>" size="15"/>
</td>
<td align="center">
<input name="Layout" type="text" P_ID="Layout" value="<?php echo $rows['Layout']; ?>" size="15"/>
</td>
<td align="center">
<input name="Decoration" type="text" P_ID="Decoration" value="<?php echo $rows['Decoration']; ?>" size="15"/>
</td>
<tr>
</table>
<input name="P_ID" type="hidden" P_ID="P_ID" value="<?php echo $rows['P_ID']; ?>"/>
<input type="submit" name="Submit" value="Submit" /></td>
<td align="center">&nbsp;</td>
</td>
</form>
</tr>
</table>
</body>
</html>

update_ac.php

<?php
// Connect to server and select database.
mysql_connect("localhost", "root", "123456")or die("cannot connect"); 
mysql_select_db("album")or die("cannot select DB");

// update data in mysql database 
$sql="UPDATE property SET Usage='".$_POST['Usage']."', Region='".$_POST['Region']."' , Street='".$_POST['Street']."' , Building='".$_POST['Building']."' , Layers='".$_POST['Layers']."' , Unit='".$_POST['Unit']."' , Construction_area='".$_POST['Construction_area']."' , Saleable_area='".$_POST['Saleable_area']."' , Price='".$_POST['Price']."' , Rent='".$_POST['Rent']."' , Contant_person='".$_POST['Contant_person']."' , Contant_Num='".$_POST['Contant_Num']."' , Layout='".$_POST['Layout']."' , Decoration='".$_POST['Decoration']."' WHERE P_ID='".$_POST['P_ID']."'";
$result=mysql_query($sql) or die ("Cannot Update Property......");


// if successfully updated. 
if($result){
echo "Successful";
echo "<BR>";
echo "<a href='list_property.php'>View Property</a>";
}

else {
echo "ERROR";
}

?>

After changing the error processing as suggested: The query is:

UPDATE property SET Usage='0', Region='Wah Chai' , Street='Tai Hang Road' , Building='Happy Valley' , Layers='a' , Unit='A' , Construction_area='1085 square feet' , Saleable_area='872 square feet' , Price='16800000' , Rent='48000' , Contant_person='Mr Yu' , Contant_Num='99968977' , Layout='3 bedrooms, including one suit' , Decoration='Yes' WHERE P_ID='1'

And the error is

You have an error in your SQL syntax; 
check the manual that corresponds to your MySQL server version 
for the right syntax to use near 
'Usage='0', Region='Wah Chai' , Street='Tai Hang Road' , Building='Happy Valley'  
 at line 1

It would help if you processed the error correctly. Then you would know what the error was rather than just that an error happened.

// update data in mysql database 
$sql="UPDATE property SET Usage='".$_POST['Usage'].
                      "', Region='".$_POST['Region'].
                      "' , Street='".$_POST['Street'].
                      "' , Building='".$_POST['Building'].
                      "' , Layers='".$_POST['Layers'].
                      "' , Unit='".$_POST['Unit'].
                      "' , Construction_area='".$_POST['Construction_area'].
                      "' , Saleable_area='".$_POST['Saleable_area'].
                      "' , Price='".$_POST['Price'].
                      "' , Rent='".$_POST['Rent'].
                      "' , Contant_person='".$_POST['Contant_person'].
                      "' , Contant_Num='".$_POST['Contant_Num'].
                      "' , Layout='".$_POST['Layout'].
                      "' , Decoration='".$_POST['Decoration'].
                      "' WHERE P_ID='".$_POST['P_ID'].
                      "'";
$result=mysql_query($sql);

if ( ! $result ) {
    echo "SQL
 $sql
Generated this error
";
    echo 'Database error: ' . mysql_errno() . ' : ' . mysql_error();
}

This mysql_* extension has been deprecated and therefore any code you write with it will at some point in time no longer work as the extension will soon be removed from new releases of PHP.