JavaScript AJAX POST does not work for mysqli

[erichmiller1989]

Hi, Geniuses:
I have followed the instructions on this page using a database on my machine.
Everything works fine.
However, the code does not work when I change all "GET"s to "POST"s and change
xmlhttp.open("GET","getuser.php?q="+str,true); xmlhttp.send();
to
xmlhttp.open("POST","getuser.php",true); xmlhttp.send("q="+str);
So what do I miss?

 

[Deleted member 2829]

So it works ok with GET ? Then why would you want to use POST instead ?
It seems pretty clear why it's not working, seeing that the PHP code gets the username from the GET request :

$q = intval($_GET['q']);

 

[erichmiller1989]

So it works ok with GET ? Then why would you want to use POST instead ?
It seems pretty clear why it's not working, seeing that the PHP code gets the username from the GET request :

$q = intval($_GET['q']);

Thanks a lot, cbreemer, for replying.
Actually I have changed $q = intval($_GET['q']); to $q = intval($_POST['q']);. It still does not work.

Then why would you want to use POST instead ?

I'd like to play with different methods/options.

 

[Antero360]

Thanks a lot, cbreemer, for replying.
Actually I have changed $q = intval($_GET['q']); to $q = intval($_POST['q']);. It still does not work.

I'd like to play with different methods/options.

Hi there,
Not sure what you mean by 'play with different methods/options'...can you clarify please?

 

[erichmiller1989]

Hi there,
Not sure what you mean by 'play with different methods/options'...can you clarify please?

Learn and compare different methods/options.

 

[Antero360]

Learn and compare different methods/options.

Not much to compare lol.
GET requests are for when you need to `get` user data from the database
POST requests are for when you need to save data to the database
PUT requests are for when you need to update/replace records on the database
PATCH requests are for when you need to update/modify records on the database
DELETE requests... self explanatory

HTTP Methods for RESTful Services

HTTP methods tutorial on how to use them for RESTful API or Web Service.

www.restapitutorial.com

 

[erichmiller1989]

Not much to compare lol.
GET requests are for when you need to `get` user data from the database
POST requests are for when you need to save data to the database
PUT requests are for when you need to update/replace records on the database
PATCH requests are for when you need to update/modify records on the database
DELETE requests... self explanatory

HTTP Methods for RESTful Services

HTTP methods tutorial on how to use them for RESTful API or Web Service.

www.restapitutorial.com

Thanks a lot, Antero360, for teaching.
Anyway, can we make the code on this page work if we change "GET" to "POST"?

 

[Antero360]

Hi, Geniuses:
I have followed the instructions on this page using a database on my machine.
Everything works fine.
However, the code does not work when I change all "GET"s to "POST"s and change
xmlhttp.open("GET","getuser.php?q="+str,true); xmlhttp.send();
to
xmlhttp.open("POST","getuser.php",true); xmlhttp.send("q="+str);
So what do I miss?

So what are you trying to do here?

 

[erichmiller1989]

So what are you trying to do here?

Learn and compare the capabilities of different methods/options.

 

[Antero360]

Learn and compare the capabilities of different methods/options.

You already mentioned that, but what I was referring to was your code. What are you trying to accomplish? Getting information back from the db, or sending information to the db?

 

[erichmiller1989]

You already mentioned that, but what I was referring to was your code. What are you trying to accomplish? Getting information back from the db, or sending information to the db?

To see how many ways to achieve the same goal.

 

[Antero360]

To see how many ways to achieve the same goal.

...you cant

 

[Antero360]

To see how many ways to achieve the same goal.

you get data back with GET
you send data with POST
you update with either PUT or PATCH
you delete with DELETE

 

[Antero360]

To see how many ways to achieve the same goal.

What are you really trying to do?

 

[Antero360]

Hi, Geniuses:
I have followed the instructions on this page using a database on my machine.
Everything works fine.
However, the code does not work when I change all "GET"s to "POST"s and change
xmlhttp.open("GET","getuser.php?q="+str,true); xmlhttp.send();
to
xmlhttp.open("POST","getuser.php",true); xmlhttp.send("q="+str);
So what do I miss?

What language is this code for?

 

[Deleted member 2829]

Thanks a lot, cbreemer, for replying.
Actually I have changed $q = intval($_GET['q']); to $q = intval($_POST['q']);. It still does not work.

I'd like to play with different methods/options.

Ah, it was not apparent from your post that you had changed the php as well.
Now, your code is basically ok but you have to keep in mind that POST is meant for HTML form submit requests. That means you have to set the content type accordingly. Add this line

xmlhttp.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');

before calling xmlhttp.send. That will make it work.

 

[erichmiller1989]

Ah, it was not apparent from your post that you had changed the php as well.
Now, your code is basically ok but you have to keep in mind that POST is meant for HTML form submit requests. That means you have to set the content type accordingly. Add this line

xmlhttp.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');

before calling xmlhttp.send. That will make it work.

Thanks for teaching, cbreemer.
I followed your instruction, but it still does not work.
It seems that the $q does not get into getuser.php at all.

 

[Deleted member 2829]

Thanks for teaching, cbreemer.
I followed your instruction, but it still does not work.
It seems that the $q does not get into getuser.php at all.

Hm, strange, I did test it. Admittedly, I used a different W3C example : https://www.w3schools.com/xml/ajax_php.asp
This uses GET and I got it to work with POST by making your changes (which did not work), then adding my line (which made it work).

 

[Ghost]

Hm, strange, I did test it. Admittedly, I used a different W3C example : https://www.w3schools.com/xml/ajax_php.asp
This uses GET and I got it to work with POST by making your changes (which did not work), then adding my line (which made it work).

Yeah, I thought the same for setting the header for content type. I wonder if the file that is receiving the POST (or GET originally) is expecting a different content-type. Worth a check

 

[erichmiller1989]

Hm, strange, I did test it. Admittedly, I used a different W3C example : https://www.w3schools.com/xml/ajax_php.asp
This uses GET and I got it to work with POST by making your changes (which did not work), then adding my line (which made it work).

Thanks a lot, cbreemer.
I changed $q = intval($_POST['q']) to $q = intval($_REQUEST['q']), it works immediately.
When I changed back to intval($_POST['q']), it works too. Quite strange, but works anyway.
Thanks again.