[Resolved] Passing array values on submit

CoderAgain

I am confused as to why some would need to be referenced with $key and some $value. Text and hidden want $value and a select works as $key.


foreach( $_POST["updatefood"] AS $key => $value ) 
 {
	$new_amount = $_POST["food_amnt"][$value];
	$uf_id = $_POST["uf_id"][$value];
	$new_gml = $_POST["uf_gml"][$key];
	$user_id = "3";

  $updtsql = "UPDATE `user_food` SET `amount` = '$new_amount', `g_ml` = '$new_gml' WHERE `uf_id` = '$uf_id' AND `user_id` = '$user_id' LIMIT 1 ;";
	mysql_query($updtsql) or die("Query failed : " . mysql_error());
//  echo "numb of rows added with update " . mysql_affected_rows() . "<BR>";
	}

<input name=\"updatefood[]\" type=\"checkbox\"  value=\"$i\"  onclick=\"SetState(this, this.form.food_amnt$i, this.form.uf_gml$i)\" />

<input name=\"uf_id[]\" id=\"uf_id$i\" type=\"hidden\" value=\"$uf_id\"  />
<input type=\"text\" name=\"food_amnt[]\" id=\"food_amnt$i\" value=\"$uf_amount\" />
<SELECT  name=\"uf_gml[]\" id=\"uf_gml$i\" disabled>
	<option value=\"0\" $sel0>Grams</option>
	<option value=\"1\" $sel1>ML</option>
</SELECT>

Anyone know why this might be? The code works, I am just stumped as to why the difference?

Thanks,
Sonya

kevinc

I think this is a classic case of using code that you don't fully understand.

When you're using the foreach() statement, it us used as follows.

$test_array = array (
"tree"=>"oak",
"fruit"=>"apple",
"phone"=>"nokia",
"ripoff"=>"microsoft",
);
foreach($test_array as $TYPE_OF_THING=>$THING_NAME) {
print "An example of a type of $TYPE_OF_THING would be a $THING_NAME.<br>";
}

From that, you should be able to see what actually happens with a foreach statement. The variable preceeding the "=>" is used to store the NAME of the corresponding element in the array, where the variable after "=>" is the actual value of that element. It doesn't matter if it's called $key or $value or $hi_mom, as long as it conforms to PHP's variable standards.

Hope this helps.

Kevin

CoderAgain

I have always shied away from Arrays, now I am trying to make them my new best friend.

What I have done is used $i to represent the row number of database output, the position in the array and also the HTML <TR> row. My goal is to let the user change values in the row, after checking the checkbox to enable them, then click update to change the database. The $i lets me know which row they are working with, hence $value = row number. The other two values pass just fine. Which is also what I would expect, being able to call the row number, hence also the position in the array or the value for that position in arrays.

In my brain $POST["food_amnt"][$value] is the same as saying $POST["food_amnt"][0] 0 being the position in the array, if it is the second row then the value is 1.

I guess my fogginess comes in where if there is only one row being passed then technically there should only be the 0 dimension to the array and not a 1, even if the user is changing row 1 and not row 0.

Why would it work with $value (thing name) for the text and hidden and $key (type of thing) for the drop down?

I know this is probably a rudimentary question, but one I am trying to get straight in my brain. I can grasp the foreach($test_array as $TYPE_OF_THING=>$THING_NAME) {
print "An example of a type of $TYPE_OF_THING would be a $THING_NAME.<br>";
} example.

Thanks,
Sonya

kevinc

That's not really the best way to do it! If you have 10 records, and the guy decides to delete row 5 and edit row 7, you're going to delete the 5th row, leaving only NINE records, and you'll delete the wrong row. Rather, in a case like this, you need to use primary key's in your mySQL table. To do this, add an "id" field which is auto incrementing, and set it as the primary key. Once you've done this, you can have a hidden variable in your form called "id" which would contain the variable of that record. That way, you don't need to use tricky 2 dimensional arrays, and it minimizes errors on your side.

How I'd do something like this, would be to loop through all the available records, and print the <tr> for each one, which would include a "checkbox" to determine if they do want to edit it, the editable regions, and a hidden id field. Then, when we receive the form, we'd loop through the received stuff using foreach() (Remember, we're using a 1 dimensional array (<input type="hidden" name="id[]" value="'.$row["id"].'">) ) , checking the "checkbox" element of the array. If this is SET, we'd continue to make the necessary changes to that specific row, and we'd use the WHERE id='id_value' to know which row to change.

It's all quite simple really 😉

Hope this helps you!

Kevin

CoderAgain

So, my thinking is not sooo off. Already did that, that is what the $uf_id field is. If I use the unique value $uf_id, which also identifies the row in the table that I want to update, how do I get the values for the other fields where the id is now the index and no longer the position in the array?

output from browser

How do I get the value of the food_amnt field?

Thanks,
Sonya

CoderAgain

I set the value inside the [] for each row to the index id - works!!

Thanks! for all of your help.

On to the next challenge...passing multiple rows from one page to the other... and hints before I attack? ;-)

-Sonya

kevinc

You've answered your own question without actually being aware of it 😉

See, if I do the following:

for($count=0;$count<5;++$count) {
<input type="hidden" name="values[]" value="some arb $count value">
}

Now, if I receive that, I can go:

foreach($_GET['values'] as $single_value) {
print 'The value in this element of the array is :'.$single_value;
}

So basically, you can store how ever many you want in there 🙂

Just have a couple of variables, ie : names[],numbers[] etc... the possiblities are endless 😉