how to send data to mysqli with an index number (prepared statement) - php

Question

I am creating an array from dynamic created input fields and then send the array over to php, in php I create a foreach loop and try to insert it into my database.
I have created a foreach loop for my array and insert the values like that in my database, however my problem is: You cannot bind a variable with an index number to your query string. I have already verified whether it's actually an array what I am sending and the answer is: Yes. it is an array.
$stmt = $conn->prepare('INSERT INTO vv(event_id, vvType, vvCosting) VALUES (?, ?, ?)');
foreach ($example as $index => $value) {
$stmt->bind_param('iss', $id, $example, $example_costs);
$id = $id;
$example = $value;
$example_costs = example_costs[$index]; //this DOES NOT work
$stmt->execute();
}
So what I want would be the following: Create one foreach loop for my $example variable and based on the index numbers it has also insert the data from the variable example_costs and insert that in the database as well. You shouldn't worry about whether the index value exists or not in my example_costs variable, since they're "pairs".
I know the problem is that I cannot bind my variable like this:
$example_costs[$index]
So now my question is: How can I bind my variable like the above? But in a way php DOES accept? Or do I need to create 2 foreach loops? --> Something I would rather NOT do.

Answer 1

You didn't specify what exactly you mean by "doesn't work" (i.e. you didn't describe what is going wrong or what behaviour you're seeing), but here's what I can observe just from the code:
1) You have (what appears to be) a typo: I expect example_costs[$index]; should really be $example_costs[$index];.
2) Assuming 1 is fixed, you're also overwriting the values of the variables $example and $example_costs, which are the ones you're trying to loop over, whilst the loop is still going on. Clearly this will destroy the original arrays and make them impossible to re-use next time it tries to loop.
In this situation, and as a general point of good coding practice, don't re-use variable names to represent two different things in the code - especially when you are still in the middle of using them for their original purpose!
In reality you don't really need these separate variables in the bind statement anyway. This should do the job:
$stmt = $conn->prepare('INSERT INTO vv(event_id, vvType, vvCosting) VALUES (?, ?, ?)');
foreach ($example as $index => $value) {
$stmt->bind_param('iss', $id, $value, $example_costs[$index]);
$stmt->execute();
}
The rest is either incorrect (over-writing the $example array, for instance) or redundant ($id = $id for instance - assigning a variable its own value is the very definition of pointless).