problem with inserting multiple string POST in a database table by json_encode()

I use jQuery to add a new input. Each row in table contains several inputs, and I want to add the data to the database as an array:

<table>
tr 1: <tr>
<input name="name" value="Translate">
<input name="explanation" value="Searches">
<input name="tv" value="Email">
</tr>
<br>
tr 2: <tr>
<input name="name" value="Phone">
<input name="explanation" value="Chat">
<input name="tv" value="Business">
</tr>
tr 3: <tr>
<input name="user" value="jimi">
</tr>
</table>

DEMO

values for tr 1 is: Translate & Searches & Email

values for tr 2 is: Phone & Chat & Business

values for tr 3 is: jimi

I use json_encode() on tr 1 and tr 2 to encode data and insert it together into the database. tr 3 is not in that array, it is alone value:

$data = array(
    'units' => json_encode(
                 array(
                 'name' => $this -> input -> post('name'),
                 'explanation' => $this -> input -> post('explanation'),
                 'tv' => $this -> input -> post('tv')
                )
    ),
    'user' => $this -> input -> post('user')
);
$this -> db -> insert('hotel_submits', $data);

The problem here is that only values "tr 2" inserted into the database.

I want value both(tr 1 and tr 2) together to be insert in the database.

I'm having in database:

{"name":Phone,"explanation":Chat,"tv":Business}

and I want this

{"name":Translate,"explanation":Searches,"tv":Email, "name":Phone,"explanation":Chat,"tv":Business}

UPDATE:

If there is several checkbox in each tr (1 & 2) and some of them are checked, How are inserted(they) in the database as below:

DEMO

<table>
 tr 1:
<tr>
    <input name="name" value="Translate">
    <input name="explanation" value="Searches">
    <input name="tv" value="Email">
    <input type="checkbox" name="c开发者_运维百科heckbox[]" value="Mootools" checked> 
    <input type="checkbox" name="checkbox[]" value="PowerTools" checked>
    <input type="checkbox" name="checkbox[]" value="Read">
</tr>


 tr 2:
<tr>
    <input name="name" value="Phone">
    <input name="explanation" value="Chat">
    <input name="tv" value="Business">
    <input type="checkbox" name="checkbox[]" value="Clientcide"> 
    <input type="checkbox" name="checkbox[]" value="Library" checked> 
    <input type="checkbox" name="checkbox[]" value="Framework" checked>
</tr>


 tr 3:
<tr>
    <input name="user" value="jimi">
</tr>
</table>

I want in database:

[{"name":"Translate","explanation":"Searches","tv":"Email", "checkbox":["Mootools","PowerTools"]},{"name":"Phone","explanation":"Chat","tv":"Business", "checkbox":["Library","Framework"}]

Since inputs in your rows share their names, the inputs in the last row rewrite values of other inputs. To overcome this, you need to assign names with [] and iterate over posted data:

 <table>
tr 1: <tr>
<input name="name[]" value="Translate">
<input name="explanation[]" value="Searches">
<input name="tv[]" value="Email">
</tr>
<br>
tr 2: <tr>
<input name="name[]" value="Phone">
<input name="explanation[]" value="Chat">
<input name="tv[]" value="Business">
</tr>
tr 3: <tr>
<input name="user" value="jimi">
</tr>
</table>

$units = array();
$names = $this->input->post('name');
$explanations= $this->input->post('explanation');
$tvs= $this->input->post('tv');
//this works ONLY if you have equal number of names, explanations and tvs
foreach ($names as $idx=>$name){
    $units[] = array(
        'name'=>$name, 
        'explanation'=>$explanations[$idx],
        'tv'=>$tvs[$idx]
    );
}

$data = array('units'=>json_encode($units), 'user'=>$this -> input -> post('user'));
$this -> db -> insert('hotel_submits', $data);

This code is not ideal, but it should work, so it's a good starting point. Also, you can't have what you want with json_encode, so it will look like

[{name:..., explanation:..., tv:...},{name:..., explanation:..., tv:...}]

In fact you can, but than you'll have hard time generating and parsing it.

Update well, that's tough. The idea is to assign indexes to your inputs explicitly, i.e.

tr1:name[0], explanation[0], tv[0], checkbox[0][],checkbox[0][],checkbox[0][]         
tr2:name[1], explanation[1], tv[1], checkbox[1][],checkbox[1][],checkbox[1][]

And the loop becomes

$checkboxes= $this->input->post('checkboxes');
foreach ($names as $idx=>$name){
    $units[] = array(
        'name'=>$name, 
        'explanation'=>$explanations[$idx],
        'tv'=>$tvs[$idx],
        'checkboxes'=>$checkboxes[$idx]
    );
}