PHP json_encode and insert data to database

I use codeigniter. I want to insert all the information in one field of myself database table by json_encode, this is my information(all information are related. It is not clear that the user registration several html. it is dynamic):
Example: http://jsfiddle.net/AQPwv/2/


<input name="name_r[1][]" value="hi">
<p>
    <input name="units[1][]" value="how">
    <input type="text" name="units[1][]" value="2" style="width:20px;">
    <input type="text" name="units[1][]" value="256314" style="width:65px;">
    <input name="units[1][]" value="fine">
    <input type="text" name="units[1][]" value="4" style="width:20px;">
    <input type="text" name="units[1][]" value="854621" style="width:65px;">
    <p>
        <input type="text" name="price_change[1][]" value="21466" style="width:75px;">
        <input type="text" name="price_change[1][]" value="54219" style="width:75px;">
        <input type="text" name="price_change[1][]" value="48752" style="width:65px;">
        <input type="text" name="price_change[1][]" value="86541" style="width:75px;">
        <input type="text" name="price_change[1][]" value="47276" style="width:75px;">
        <input type="text" name="price_change[1][]" value="74538" style="width:65px;">
        <p>
            <hr>
<p>
    <input name="name_r[2][]" value="hello">
    <p>
        <input name="units[2][]" value="Library">
        <input type="text" name="units[2][]" value="5" style="width:20px;">
        <input type="text" name="units[2][]" value="95641" style="width:65px;">
        <input name="units[2][]" value="khobee">
        <input type="text" name="units[2][]" value="6" style="width:20px;">
        <input type="text" name="units[2][]" value="84527" style="width:65px;">
        <input name="units[2][]" value="PowerTools ">
        <input type="text" name="units[2][]" value="7" style="width:20px;">
        <input type="text" name="units[2][]" value="75462" style="width:65px;">
        <p>
            <input type="text" name="price_change[2][]" value="8457" style="width:75px;">
            <input type="text" name="price_change[2][]" value="134" style="width:75px;">
            <input type="text" name="price_change[2][]" value="76144" style="width:65px;">
            <input type="text" name="price_change[2][]" value="956414" style="width:75px;">
            <input type="text" name="price_change[2][]" value="7546" style="width:75px;">
            <input type="text" name="price_change[2][]" value="123" style="width:65px;">
            <input type="text" name="price_change[2][]" value="84541" style="width:75px;">
            <input type="text" name="price_change[2][]" value="654" style="width:75px;">
            <input type="text" name="price_change[2][]" value="8165" style="width:65px;">
            <input type="text" name="price_change[2][]" value="2145" style="width:75px;">
            <input type="text" name="price_change[2][]" value="354" style="width:75px;">
            <input type="text" name="price_change[2][]" value="4774" style="width:65px;">

I would like to have in the database:


[{
    "name_r": "hi",
    "units": ["how", "2", "256314"],["fine", "4", "854621"],
    "price_change": ["21466", "54219", "48752"],["86541", "47276", "74538"],
}, {
    "name_r": "hello",
    "units": ["Library", "5", "95641"],["khobee", "6", "84527"],["PowerTools ", "7", "75462"],
    "checkbox_units": ["8457", "134", "76144"],["956414", "7546", "123"],["84541", "654", "8165"],["2145", "354", "4774"]
}]


i use of this PHP code:


$name_r=$this->input->post('name_r');
$units=$this->input->post('units');
$price_change=$this->input->post('price_change');

foreach($name_r as $key => $value)
{
    $arr[]=array(
     'name_r'=>$value['0'],
     'units'=>$units[$key],
     'price_change'=>$price_change[$key]
    );
}

$json=json_encode($arr);

but this php code inserted as(i not want this):


[{
    "name_r": "hi",
    "units": ["how", "2", "256314", "fine", "4", "854621"],
    "price_change": ["21466", "54219", "48752", "86541", "47276", "74538"]
},

{
    "name_r": "hello",
    "units": ["Library", "5", "95641", "khobee", "6", "84527", "PowerTools ", "7", "75462"],
    "price_change": ["8457", "134", "76144", "956414", "7546", "123", "84541", "654", "8165", "2145", "354", "4774"]
}]

How is it and what do i do?
With respect

The format you want is invalid JSON:

[{
    "name_r": "hi",
    "units": ["how", "2", "256314"],["fine", "4", "854621"],
    "price_change": ["21466", "54219", "48752"],["86541", "47276", "74538"],
}, {
    "name_r": "hello",
    "units": ["Library", "5", "95641"],["khobee", "6", "84527"],["PowerTools ", "7", "75462"],
    "checkbox_units": ["8457", "134", "76144"],["956414", "7546", "123"],["84541", "654", "8165"],["2145", "354", "4774"]
}]

How can we have a format similar to this, For easy select in future by “foreach” or so on (select * from table …), namely:

For example in the “units 2” values as be separated:

[“Library”, “5”, “95641”]
&
[“khobee”, “6”, “84527”]
&
[“PowerTools”, “7”, “75462”]
and so on…

Next, I want separating each one as:

[
{“Library”}
{“5”}
{“95641”}
]
&
[
{“khobee”}
{“6”}
{“84527”}
]
&
[
{“PowerTools”}
{“7”}
{“75462”}
]

How can do?