PDO: PHP foreach array returning null

Question

I did a very short and simple PHP .

The output is an array in json. However it doesn't work .

The array-items are always null.

I guess it must have something to do with mistakenly calling the db table columns

('id' => $row->MASTER_ID).

Whereas 'MASTER_ID' is the name of the column in my db.

I'd be very glad if someone could point me in the right direction. My script looks as follows:

<?php
$db = new PDO('mysql:host=xxx;dbname=xx;charset=utf8mb4', 'xx', 'xxx');
$month = date('Y-m');
$monthwild = "$month%";
$sql   = ("SELECT * FROM MASTER WHERE START_DATE LIKE '". $monthwild ."'");
$out = array();

foreach($db->query($sql) as $row) {
    $out[] = array(
        'id' => $row->MASTER_ID,
        'title' => $row->MASTER_TITLE,
        'start' => strtotime($row->MASTER_START),
        'end' => strtotime($row->MASTER_END)
    );
} 

echo json_encode(array('success' => 1, 'result' => $out));
exit;
?>

I'm new to PDO (used to do things like this with mysql) and

I didn't get it yet and didn't find the right resources

A very good tutorial: phpdelusions.net/pdo

DTH
– DTH

2016-03-30 09:45:33 +00:00
Commented Mar 30, 2016 at 9:45 — DTH
– DTH, Commented Mar 30, 2016 at 9:45
@DTH thanks, that looks good!

sardine
– sardine

2016-03-30 12:12:03 +00:00
Commented Mar 30, 2016 at 12:12 — sardine
– sardine, Commented Mar 30, 2016 at 12:12

fusion3k · Accepted Answer · 2016-03-30 09:49:31Z

1

PDO::query “executes an SQL statement, returning a result set as a PDOStatement object,” not a row.

You have to put the result in a variable and then retrieve rows from this variable:

$result = $db->query( $sql );
while( $row = $result->fetchObject() )
{
    (...)
}

As alternative, you can set a default fetch mode and then retrieve single rows with:

$result = $db->query( $sql );
$result->setFetchMode( PDO::FETCH_OBJ );
while( $row = $result->fetch() )
{
    (...)
}

Edit:

Actually, also direct foreach works, but without a specific fetch mode it returns enumerated and associative result:

foreach( $db->query( $sql ) as $row  )
{
    $id = $row['MASTER_ID'];
    // $id = $row[0]; // ← Alternative
}

To use objects with direct foreach you have to use this syntax:

foreach( $db->query( $sql, PDO::FETCH_OBJ ) as $row  )
{
    $id = $row->MASTER_ID;
}

Read more about PDO::query
Read more about PDOStatement

edited Mar 30, 2016 at 9:49

answered Mar 30, 2016 at 9:36

fusion3k

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1 Comment

sardine Over a year ago

GREAT, thank you so much! This works perfectly! I used the php example from bootstrap calendar github.com/Serhioromano/bootstrap-calendar hence i didn't question the foreach part :/

Microgamer · Accepted Answer · 2016-03-30 09:39:07Z

1

I'd say that your definition of $monthwild is wrong. The right notation for that what you want to write is: $monthwild = $month."%"; In your script is the content of $monthwild the string "$month%" Now is the content of $monthwild the string %

I hope you can understand that. It is not easily described.

answered Mar 30, 2016 at 9:39

Microgamer

217 bronze badges

1 Comment

sardine Over a year ago

Thank you very much! I think i can follow - that makes sense and does seem more 'correct'. But actually $monthwild = "$month%"; does work as intended too, don't ask me why - i just tried to code what seemed most obvious to a noob like i am :)

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