I was looking for a way to submit data through a button so that the data will be saved or updated in database, without reloading. Now updating and inserting of data works. But I have used dataString a javaScript variable. I thought through this dataString variable post data are passed. But when I removed that variable from my code data insert or update was still working. So how the passing of data working here.
How post method gets the data from my ajax call here.
<html>
<title>Registration</title>
<body>
<?php
$servername = "localhost";
$username = "root";
$password = "nopass";
$dbname = "registration_project";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
?>
<div style="width:350px">
<div style="float:left;width:40%">
Id:<br/><br/>
First Name:<br/><br/>
Last Name:<br/><br/>
Age:<br/><br/>
</div>
<div style="float:left;width:60%">
<form action="" method="post">
<input type="number" id="id_id" name="id" value=<?php
if (isset($_POST['id']))
echo $_POST['id'];
?>><br /><br />
<input type="text" id="id_fname" name="fname" value=<?php
if (isset($_POST['fname']))
echo $_POST['fname'];
?>><br /><br />
<input type="text" id="id_lname" name="lname" value=<?php
if (isset($_POST['lname']))
echo $_POST['lname'];
?>><br /><br />
<input type="number" id="id_age" name="age" value=<?php
if (isset($_POST['age']))
echo $_POST['age'];
?>><br /><br />
<input type="submit" id="id_submit" name="submit">
</form>
</div>
</div>
<script src="js/jquery-1.11.3.js"></script>
</body>
</html>
<?php
if (isset($_POST['id']))
echo $_POST['id'] . "<br/><br/>";
if (isset($_POST['fname']))
echo $_POST['fname'] . "<br/><br/>";
if (isset($_POST['lname']))
echo $_POST['lname'] . "<br/><br/>";
if (isset($_POST['age']))
echo $_POST['age'] . "<br/><br/>";
?>
<?php
if (isset($_POST['submit'])) {
$fname = $_POST['fname'];
$lname = $_POST['lname'];
$age = $_POST['age'];
$sql = "select max(id) from registration";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
// output data of each row
while ($row = $result->fetch_assoc()) {
$id = $row["max(id)"];
}
} else {
echo "0 results";
}
if ($id==$_POST['id']) {
$id = $_POST['id'];
$sql = "update registration set firstName='$fname', lastName='$lname', age=$age where id=$id";
mysqli_query($conn, $sql);
} else {
$id=$_POST['id'];
$sql = "Insert into registration(id,firstName,lastName,age) values($id,'$fname','$lname',$age)";
mysqli_query($conn, $sql);
}
}
mysqli_close($conn);
?>
<script>
$("#id_submit").click(function(e) {
var id = $("#id_id").val();
var fname = $("#id_fname").val();
var lname = $("#id_lname").val();
var age = $("#id_age").val();
var dataString = "id="+id+ '&fname='+fname+'&lname='+lname+'&age='+age;
//console.log(dataString);
$.ajax({
type:'POST',
data:dataString,
url:'Registration.php',
success:function(data) {
}
});
});
</script>
Your click handler doesn't have e.preventDefault() in it. So after the AJAX call is sent, the form is also submitted normally. So even if you don't fill in dataString, the database will be updated from the form.
To make it only use AJAX, you should call e.preventDefault(). You also need to submit a value for the submit parameter, because the PHP code uses if(isset($_POST['submit'])) to know if it should process the form parameters.
$("#id_submit").click(function(e) {
e.preventDefault();
var id = $("#id_id").val();
var fname = $("#id_fname").val();
var lname = $("#id_lname").val();
var age = $("#id_age").val();
var dataString = "submit=submit&id="+id+ '&fname='+fname+'&lname='+lname+'&age='+age;
//console.log(dataString);
$.ajax({
type:'POST',
data:dataString,
url:'Registration.php',
success:function(data) {
}
});
});
In your case, values aren't getting passed. More over, the way you're trying to do ( ?id=...&fname=... etc) would be for passing it with $_GET.
You have to make something similar to :
$.ajax({
type:'POST',
data: { id : $("#id_id").val(),
fname : $("#id_fname").val(),
lname : $("#id_lname").val(),
age : $("#id_age").val()
},
url:'Registration.php',
success:function(data) {
// code
}
});
But when I removed that variable from my code data insert or update was still working. So how the passing of data working here.
Answer
When you remove var dataString all the fields having name attribute are automatically submitted along with form