bind_param(): Number of variables doesn't match number of parameters in prepared statement

Question

Basically the problem is I have a column of dates in my database table and I want to count the number of each particular date and have it stored in an array.I've busted my head around this problem for a week and so far I've come up with this.

<?php

function vref($arr) {
 if (strnatcmp(phpversion(),'5.3') >= 0) {
  $refs = array();
  foreach($arr as $key => $value) $refs[$key] = &$arr[$key];
  return $refs;
 }
 return $arr;
}

$mysqli = new mysqli("localhost", "root","" , "ti_project");

$bind = 'sssss';
$feedbackdate = array($bind);

$query = "SELECT dateTime FROM feedback";
$result = $mysqli->prepare($query);
$result->execute();
$result->bind_result($Date);
while ($result->fetch()){
    $feedbackdate[] = array($Date);
}

$rawQuery = 'SELECT COUNT(*) FROM feedback WHERE dateTime IN (';
$rawQuery .= implode(',',array_fill(0,count($feedbackdate),'?'));
$rawQuery .= ')';

$stmt = $mysqli->prepare($rawQuery);
call_user_func_array(array($stmt,'bind_param'),vref($feedbackdate));
$stmt->execute();
$stmt->bind_result($count);

while ($stmt->fetch()) {
    printf ("%s\n", $count);
}

?>

But here I get the error

mysqli_stmt::bind_param(): Number of variables doesn't match number of parameters in prepared statement.

So how to do this?

trincot · Answer 1 · 2016-01-25T17:03:31.507

0

Your parameter array consists of arrays, which I don't think is what you want:

Replace:

while ($result->fetch()){
    $feedbackdate[] = array($Date);
}

By:

while ($result->fetch()){
    $feedbackdate[] = $Date;
}

Also, you initialise your array already with one element, which makes no sense. So replace:

$feedbackdate = array($bind);

with:

$feedbackdate = array();

Then the injection of these arguments can be done a lot easier by using the optional parameter of execute():

$stmt = $mysqli->prepare($rawQuery);
$stmt->execute($feedbackdate);

edited Jan 25 '16 at 17:03

answered Jan 25 '16 at 16:49

trincot

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why will I not want an array? Date is a column and there are multiple dates and i want to count those dates. Multiple dates hence array – Saeesh Jan 25 '16 at 16:53
Because it would be an array of array as you did it, like `[ ['2016-01-18'], ['2016-01-18'], ...]`, while you need `[ '2016-01-18', '2016-01-18', ...]` – trincot Jan 25 '16 at 16:55
oh now i get it. Thanks – Saeesh Jan 25 '16 at 16:59
Ah yes, you need to replace this as well: `$feedbackdate = array($bind);` -- remove `$bind`. I added that in my answer. Not sure what you wanted to do here. – trincot Jan 25 '16 at 17:02
Oh no actually $bind is a string which contains the type of parameters i'm binding.Its needed in the array as the first element. – Saeesh Jan 25 '16 at 17:24
I see, but skip it anyway, because `s` is the default. As you had it, that argument was not arriving where you wanted it anyway. The type has to be passed as third argument to *bindParam()*. Anyway, leave it out. – trincot Jan 25 '16 at 17:40

score 0 · Accepted Answer · answered Jan 25 '16 at 16:53

I am not sure why you need to do two queries to get the result set you are looking for. This query will group the results by date and count them:

SELECT dateTime, COUNT(*) FROM feedback GROUP BY dateTime;

This will output something like:

+-----------------------+-------+
| dateTime              | count |
+-----------------------+-------+
|2016-01-25 00:00:00    | 1     |
|2016-01-24 00:00:00    | 2     |
+-----------------------+-------+

Is that the type of data you are after?

bind_param(): Number of variables doesn't match number of parameters in prepared statement

2 Answers2