$ wpdb - > get_col返回重复的数组

Question

I'm trying to get all the values for all sessions under the "session_value" column in the "wp_woocommerce_sessions" DB table.

The following code does the job but for some reason is duplicating the result 6 times, giving me 6 arrays with the exact same content.

global $wpdb;
$wooSessions = $wpdb->get_col( "SELECT session_value FROM {$wpdb->prefix}woocommerce_sessions" );
$wooCookies = implode(" ", $wooSessions);

I'm reading about OBJECT_K in the documentation which in theory discards duplicated keys but I don't know how to apply it. If I add OBJECT_K inside the get_col parenthesis the code stops working.

This is the output var_dump ($wooSessions); is giving me:

array(1) { [0]=> string(4366) "a:12:{s:4:"cart";s:2084:"a:2:{s:32:"1b4cfd194c804d1ad422a350aa2a0145…"}

array(1) { [0]=> string(4366) "a:12:{s:4:"cart";s:2084:"a:2:{s:32:"1b4cfd194c804d1ad422a350aa2a0145…"}

array(1) { [0]=> string(4366) "a:12:{s:4:"cart";s:2084:"a:2:{s:32:"1b4cfd194c804d1ad422a350aa2a0145…"}

array(1) { [0]=> string(4366) "a:12:{s:4:"cart";s:2084:"a:2:{s:32:"1b4cfd194c804d1ad422a350aa2a0145…"}

array(1) { [0]=> string(4366) "a:12:{s:4:"cart";s:2084:"a:2:{s:32:"1b4cfd194c804d1ad422a350aa2a0145…"}

array(1) { [0]=> string(4366) "a:12:{s:4:"cart";s:2084:"a:2:{s:32:"1b4cfd194c804d1ad422a350aa2a0145…"}

Here's another example using session_id and session_key:

global $wpdb;
$wooSessions = $wpdb->get_results( "SELECT DISTINCT session_id, session_key FROM {$wpdb->prefix}woocommerce_sessions GROUP BY session_key" );

Which returns the following:

Array ( [0] => stdClass Object ( [session_id] => 2149 [session_key] => 76f0552cff4af84e1963815c1fc4a14d ) ) 
Array ( [0] => stdClass Object ( [session_id] => 2149 [session_key] => 76f0552cff4af84e1963815c1fc4a14d ) ) 
Array ( [0] => stdClass Object ( [session_id] => 2149 [session_key] => 76f0552cff4af84e1963815c1fc4a14d ) ) 
Array ( [0] => stdClass Object ( [session_id] => 2149 [session_key] => 76f0552cff4af84e1963815c1fc4a14d ) ) 
Array ( [0] => stdClass Object ( [session_id] => 2149 [session_key] => 76f0552cff4af84e1963815c1fc4a14d ) ) 
Array ( [0] => stdClass Object ( [session_id] => 2149 [session_key] => 76f0552cff4af84e1963815c1fc4a14d ) )

Here's another example selecting session_id and group by session_id:

global $wpdb;
$wooSessions = $wpdb->get_results( "SELECT session_id FROM {$wpdb->prefix}woocommerce_sessions GROUP BY session_id" );

This is the result:

Array ( [0] => stdClass Object ( [session_id] => 2149 ) )
Array ( [0] => stdClass Object ( [session_id] => 2149 ) )
Array ( [0] => stdClass Object ( [session_id] => 2149 ) )
Array ( [0] => stdClass Object ( [session_id] => 2149 ) )
Array ( [0] => stdClass Object ( [session_id] => 2149 ) )
Array ( [0] => stdClass Object ( [session_id] => 2149 ) )

Any ideas that can point me in the right direction? Thanks in advance.