How to insert multiple selectbox item in one column - php

Question

I have a select box which have multiple item select facility
<select multiple="" class="form-control" name="mul[]">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
</select>
Here select box item generate dynamically from another table.so item amount can be increase or decrease.for this reason i cant use set data type.
Now i want to insert selected value in my database table.
MY table look like
id name item
1 first mul[] value
2 second mul[] value
I want to insert selected item in DB Table column named item.
Also i want to retrieve every row data.
view like
id name item
1 first 1,2,3
2 second 2,4
I tried
$select_value=$_POST['mul'];
$sql="insert into mytable (`id`, `name`, `item`) VALUES (null, 'Hallo',$select_value)";

Answer 1

Use php impload function.
http://www.w3schools.com/php/showphp.asp?filename=demo_func_string_implode
In your case it will b like
$select_value=implode(", ", $_POST['mul']);
$sql="insert into mytable (`id`, `name`, `item`) VALUES (null, 'Hallo',$select_value)";
Then insert it.. :)
Try this.. i hope it helps you

Answer 2

This will automatically changes array to string, with comma:
$select_value = join($_POST['mul'],',');

Answer 3

'implode' of php is the solution:
echo implode(",",$_POST['mul']);//here $_POST['mul'] = ['1','2','3']
It will output string "1,2,3", insert it your table.
Here is more info about implode implode
Also ,if you want to retrieve records from DB table using your option values then FIND_IN_SET() function of sql will be useful , the query will be :
SELECT * FROM mytable WHERE FIND_IN_SET('option_value',`item`) <>0