通过 PHP 函数 mysql_query 执行 SQL UPDATE 语句，可以将数据更新到 MySQL 表中。 下面是一个将记录更新到员工表中的简单示例。要更新任何表中的记录，需要使用条件子句来定位该记录。下面的示例使用主键来匹配员工表中的记录。
示例
尝试以下示例来了解更新操作。您需要提供员工 ID 才能更新员工工资。
<html>
<head>
<title>Update a Record in MySQL Database</title>
</head>
<body>
<?php if(isset($_POST['update'])) {
$dbhost = 'localhost:3036';
$dbuser = 'root';
$dbpass = 'rootpassword';
$conn = mysql_connect($dbhost, $dbuser, $dbpass);
if(! $conn ) {
die('Could not connect: ' . mysql_error());
}
$emp_id = $_POST['emp_id'];
$emp_salary = $_POST['emp_salary'];
$sql = "UPDATE employee ". "SET emp_salary = $emp_salary ".
"WHERE emp_id = $emp_id" ;
mysql_select_db('test_db');
$retval = mysql_query( $sql, $conn );
if(! $retval ) {
die('Could not update data: ' . mysql_error());
}
echo "Updated data successfullyn";
mysql_close($conn);
}else {
?>
<form method = "post" action = "<?php $_PHP_SELF ?>"> <table width = "400" border =" 0" cellspacing = "1"
cellpadding = "2">
<tr>
<td width = "100">Employee ID</td>
<td><input name = "emp_id" type = "text"
id = "emp_id"></td>
</tr>
<tr>
<td width = "100">Employee Salary</td>
<td><input name = "emp_salary" type = "text"
id = "emp_salary"></td>
</tr>
<tr>
<td width = "100"> </td>
<td> </td>
</tr>
<tr>
<td width = "100"> </td>
<td>
<input name = "update" type = "submit"
id = "update" value = "Update">
</td>
</tr>
</table>
</form>
<?php }
?>
</body></html> 
