Updating Data into MySQL

Data can be updated into MySQL tables by executing SQL UPDATE statement through PHP function mysql_query.

Below is a simple example to update records into employee table. To update a record in any table it is required to locate that record by using a conditional clause. Below example uses primary key to match a record in employee table.

Example

Try out following example to understand update operation. You need to provide an employee ID to update an employee salary.

<html>

<head>
<title>Update a Record in MySQL Database</title>
</head>

<body>
<?php
if(isset($_POST['update'])) {
$dbhost = 'localhost';
$dbuser = 'root';
$dbpass = '';

$conn = mysql_connect($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 successfully\n";

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>