Newby question - Copy row from one table to another

[Red2034]

on one page I have a btn for each row of data (in my case I am showing all the courses available from 'class_master'):

<td width="50" align="center">
<?php echo form_open('student/classes/enroll' , array('class_master' => 'form-horizontal validatable','target'=>'_top'));?>
<div class="form-actions">
<button type="submit" class="btn btn-gray"><?php echo get_phrase('enroll');?></button>
</div>
</form>                
</td>...

and on the controller page I am firing the case for the 'enroll' call listed above. Now what I would like to happen is this:

I want some of the info from that row selected to INSET into the 'class' table, and here is the code on the controller page:

function classes($param1 = '', $param2 = '')
    {      
       if ($param1 == 'enroll') {
    
       $classes = $this->db->get_where('class_master', array(
            'title'))->row();
          $data['title'] = $classes['title'];
          $this->db->insert('class', $data);
          redirect(base_url() . 'index.php?student/classes/', 'refresh');
           }

if I replace the bold code above with "any text"; it works fine, but the way it is I get this error when I click the btn...

 

 

Error Number: 1054

Unknown column '0' in 'where clause'

SELECT * FROM (`class_master`) WHERE `0` = 'title'

Filename: /public_html/Site/controllers/student.php

Line Number: 97

 

 

does anybody have any suggestions about what may be wrong

[.josh]

Your classes function doesn't know anything about $classes; it's not within its scope. You need to pass it as an argument to the function.

[Red2034]

do you mean I need to add something like this outside my classes function on the controller page:

<?php $classes = $this->db->get('class_master')->result_array();
                        foreach($classes as $row):?>

unsure how to define $classes in PHP i guess?

[.josh]

okay, somewhere in your code you are calling classes().

 

And inside classes() you have this:

 

$data['title'] = $classes['title'];

The problem is that your classes() function doesn't have access to $classes['title']. So you need to expose it to your function. Normally you do this by passing it as a parameter to the function, though there are other ways to do it, depending on when/where you are actually setting $classes['title'] vs. when/where you are calling classes().

 

For example:

$foo = 'bar';

function something() {
  echo $foo;
}

something();

This won't echo anything, because something() doesn't have access to $foo. If your error reporting is turned on and set to appropriate levels, you will actually get a notice or warning saying that you are attempting to use a variable that doesn't exist.

 

So instead, you would do something like this:

 

$foo = 'bar';

function something($foo) {
  echo $foo;
}

something($foo);

Now 'bar' will echo, because you are passing it to the function.

 

Alternatively, you can do this:

 

$foo = 'bar';

function something() {
  global $foo;
  echo $foo;
}

something();

That declares that you want the function to look for $foo in the global context. So it will find it there and reference that. However, it is a bad idea to do it this way. This is considered scope creep, and can lead to unexpected behavior.

 

Another alternative is if everything including the function is actually within a class. Then you could do something like this:

 

class something {
  var $foo;

  function doSomething() {
    echo $this->foo;
  }
}

$blah = new something();
$blah->foo = 'bar';
$blah->doSomething();

I show this example because this is essentially what you seem to be doing already with $this->db in your function. Though in practice, you should have getter and setter methods for it instead of directly accessing the value, something like this:

 

class something {
  var $foo;

  function get_foo() {
    return $this->foo;
  }

  function set_foo($foo) {
    $this->foo = $foo;
  }

  function doSomething() {
    echo $this->get_foo();
  }
}

$blah = new something();
$blah->set_foo('bar');
$blah->doSomething();

[Red2034]

ah!

 

$foo = 'bar';

 

is not global - this is my issue - let me now play around with these ideas...

[Red2034]

but honestly I thought I was declaring $classes with this:

 

 

$classes = $this->db->get_where('class_master', array(
            'title'))->row();

[.josh]

well, you are assigning something to $classes with that. The problem is your classes() function doesn't know anything about it. So you have to expose it to your classes function.

[Red2034]

unfortunately, I was not able to pass along the para. into that classes function... But I did realize that those para already exists on the first page that contains the btn - so I just added the code to the btn itself...

<?php $classesMaster = $this->db->get('class_master')->result_array();
                        foreach($classesMaster as $row):?>
 
                        <tr><td width="50" align="center">
          <button type="submit" class="btn btn-gray">
          <?php echo get_phrase('enroll');
          $classes = $this->db->get('class_master', ('title'))->row();
          $data['title'] = $row['title'];
          $this->db->insert('class', $data);?></button>

so this is adding the title to the 'class' table correctly, but it adds all titles that exists in the 'class_master' table everytime I refresh the page?!?!?

 

and I thought that I would call '$classes' where I have $row listed above but it throws an error.

 

"DataTables warning (table id = 'DataTables_Table_1'): Requested unknown parameter '1' from the data source for row0"

 

any suggestion with this new approach?

[Red2034]

I am passing a single paramater in, but still trying to figure out how to pass the array in:
btn display page code:

<?php $classesMaster=$this->db->get('class_master')->result_array(); foreach($classesMaster as $row):?>

<tr><td width="50" align="center">
<?php echo form_open('student/classes/enroll' , array($classesMaster));?>
<div class="form-actions">
<button type="submit" class="btn btn-gray">
<?php echo get_phrase('enroll');?></button></div></form>

controller page code:

function classes($param1 = '', $param2 = '', $classesMaster)
{
if ($param1 == 'enroll') {

$data['title'] = $classesMaster['title'];
$data['status'] = 'not attempted';
$data['enroll_date'] = date("Y-m-d");
$this->db->insert('class', $data);
redirect(base_url() . 'index.php?student/classes/', 'refresh');
}

title is still coming up NULL... I get what you are saying about passing the value of $classesMaster into this controller page function (I DO) but I just dont know php well enough to know how to pass and parse the array... I started this project by grabbing some code from several places online and have been piecing them together and for the most part I have made it work but this is the only thing that is not...

can you help me a bit more (anyone)?