Confused about adding array from post to database - php

Question

I have a complicated array (at least it looks complicated to me). I have a form where you select a person, a start time and an end time. You can then add more people by clicking a + button. So I named the three select fields like "select_dancer[]" for an array.
When I print_r my results, it looks like this:
Array
(
[month_year] => 2011-11
[select_dancer] => Array
(
[0] => 1
[1] => 2
)
[time_from] => Array
(
[0] => 12:00pm
[1] => 1:00pm
)
[time_to] => Array
(
[0] => 12:30pm
[1] => 1:30pm
)
)
Basically, the key 0 is one person, and key 1 is another. Etc. I'm having trouble getting my head around adding this to the database. My table is basically: id, date, dancer, from, to. So I want it so I can "group" each key together and submit the values to the database.
If anyone could help me out, that would be great.

Answer 1

An easier approach to the field grouping would be something like this in your HTML
<input name="dancer[0][id]" ...
<input name="dancer[0][time_from]" ...
<input name="dancer[0][time_to]" ...
As each group is added, increment the number in the first square-brackets.
Your resulting $_POST array would then look like
Array
(
[month_year] => 2011-11
[dancer] => Array
(
[0] => Array
(
[id] => 1,
[time_from] => 12:00pm
[time_to] => 12.30pm
)
[1] => Array
(
[id] => 2
[time_from] => 1:00pm
[time_to] => 1:30pm
)
)
)
You can then iterate the $_POST['dancer'] array for each group of values, eg (very simplified)
foreach ($_POST['dancer'] as $dancer) {
if (!isset($dancer['id'], $dancer['time_from'], $dancer['time_to'])) {
throw new Exception('All fields are required');
}
$id = $dancer['id'];
$timeFrom = $dancer['time_from'];
$timeTo = $dancer['time_to'];
}

Answer 2

Try something like this:
for ($i = 0; $i < count($mydata["select_dancer"]); $i++)
{
$insert = "insert into mytable (date, dancer, from to) values ($mydata['month_year'], $mydata['select_dancer'][$i], $mydata['time_from'][$i], $mydata['time_to'][$i])";
do_sql_insert($insert);
}
With this, you're vulnerable to injection attacks and the chance that a particular dancer doesn't have a represented index in every sub-array. Go with what #Phil wrote if you can.

Answer 3

If each of element select_dancer, time_from, time_to has the same array size, you can easily check for any of that and do loop using it:
WARNING: UNTESTED CODE
foreach($post_array['select_dancer'] as $key => $value)
{
$sql = "INSERT INTO dance_table(date, dancer, from, to) ";
$sql .= "VALUES('{$wherever_you_got_the_date}', '{$value}',";
$sql .= "'" . $post_array['time_from'][$key] . "', ";
$sql .= "'" . $post_array['time_from'][$key] . "')";
}

Answer 4

foreach($_POST[select_dancer] as $key => $value) {
$sql = "insert into table set dancer=$value,from='{$_POST['time_from'][$key]}',to={$_POST['time_to'][$key]}';"
//execute the SQL ...
}
of course in real life got to deal will protecting against SQL injection etc, but the principle of accessing the arrays is the same