how can I connect these two tables in sql?

Question

i need to take only the items from the table "__sobi2_item" that are in the same country of the user.And use this results for the rest of the function Showupdatelisting. This is my php script:

<?php
function showUpdatedListing()
    {

//i found the user country field value...
    global $database;
    $user =& JFactory::getUser();
    $userId = $user->get( 'id' );
    $sql = "SELECT (id) FROM #__community_fields WHERE fieldcode= 'FIELD_COUNTRY'";
    $database->setQuery( $sql );
    $fieldID = $database->loadResult();
    $sql = "SELECT (value) FROM #__community_fields_values WHERE field_id= {$fieldID} && user_id= {$userId}";
    $database->setQuery( $sql );
    $usercountry = $database->loadResult();
// From all the entries i take only ones that have country field like the user has...
    $query = "SELECT `data_txt`, `itemid`, `fieldid` FROM `#__sobi2_fields_data` WHERE (`fieldid` = 6) AND ('data_txt' = {$usercountry})";
    $database->setQuery($query);
    $ResultsArray = $database->loadObjectList();

// We need something here like a Query to load only the entries from $ResultsArray... ??
//....instead of this...
    $config =& sobi2Config::getInstance();
        $database = $config->getDb();
        $now = $config->getTimeAndDate();

        $query = "SELECT itemid FROM #__sobi2_item WHERE (published = 1 AND publish_down > '{$now}' OR publish_down = '{$config->nullDate}') ORDER BY last_update DESC LIMIT 0, 30";
        $database->setQuery($query);
        $sids = $database->loadResultArray();
// ......... show update function goes on...

?>

can anyone help me to connect and adjust these query? thanks.

NB:with the last query (4) i need to filter items of the $ResultsArray taking only ones published and ordering them by last_update. i know it is wrong and now there is no connection with the query before. This is how i have tables in mysql:

_sobi2_fields_data:

itemid fieldid data_txt --->(is a description column for each field)

_sobi2_item:

itemid published --->( 1 if true, 0 if false ) last_update --->(date of the last update for the item, also equal to the publication date if there are no changes)

thanks.

Answer 1

I don't know what you are trying to ask as well. Your last query (number 4) doesn't make sense to me, how is it linked to the above queries?

[EDIT] I've linked your 4th table above assuming itemid is the primary key for the items in sobi2_item table and that the value is linked to the sobi_fields_data table via itemid.

SELECT 
  cf.id,
  sfd.data_txt,
  sfd.itemid,
  sfd.fieldid
FROM #__community_fields cf
INNER JOIN #__community_fields_values cfv ON cf.id=cfv.field_id
INNER JOIN #__sobi2_fields_data sfd ON cfv.value=sfd.data_txt
INNER JOIN #__sobi2_item si ON sfd.itemid=si.itemid
WHERE cf.fieldcode='FIELD_COUNTRY'
AND cfv.user_id=$userId
AND sfd.fieldid=6
AND si.published=1
AND (si.publish_down > '{$now}' OR si.publish_down = '{$config->nullDate}')
ORDER BY si.last_update DESC LIMIT 0, 30

Good luck!