Question

Trying to select unique years from timestamp column in a table but so far unsuccesful. There are about 50 rows with 3 unique years between them.

$getyears = $dbh->prepare("SELECT DISTINCT DATE_FORMAT(timestamp, '%Y') as timestamp FROM press");
$getyears->execute();
$years = $getyears->fetchAll(PDO::FETCH_ASSOC);

print_r($years);

The result of this is:

Array ( [0] => Array ( [timestamp] => ) )

There should be three different years.

I’m no expert in MySQL and quite new to PDO. Can’t see where I’m going wrong.

Updated

I enclosed timestamp with back ticks but still the same result.

Printing the error info print_r($getyears->errorInfo()); returned:

Array ( [0] => 00000 [1] => [2] => )

timestamp is a int type field and after a double check, the table as a whole definitely contains 3 unique years.

Updated 2

Just a bit more info:

All rows have either of the following in the timestamp field (int(11)):

1230587568
1262123568
1356817968

Answer 1

You can show the error with

print_r($dbh->errorInfo());

or

print_r($getyears->errorInfo());

According to Reserved Words, it is allowed to use timestamp unquoted. Although, it is a good habit to quote it with backticks anyway.

date_format works with a date type and not with an int type. If timestamp is a unix timestamp (seconds since 1970-01-01), you can try from_unixtime instead.