function dbtng_example_advanced_list

Render a filtered list of entries in the database.

DBTNG also helps processing queries that return several rows, providing the found objects in the same query execution call.

This function queries the database using a JOIN between users table and the example entries, to provide the username that created the entry, and creates a table with the results, processing each row.

SELECT e.pid as pid, e.name as name, e.surname as surname, e.age as age u.name as username FROM {dbtng_example} e JOIN users u ON e.uid = u.uid WHERE e.name = 'John' AND e.age > 18

See also

db_select()

http://drupal.org/node/310075

Related topics

File

dbtng_example/dbtng_example.module, line 310

Code

function dbtng_example_advanced_list() {
    $output = '';
    $select = db_select('dbtng_example', 'e');
    // Join the users table, so we can get the entry creator's username.
    $select->join('users', 'u', 'e.uid = u.uid');
    // Select these specific fields for the output.
    $select->addField('e', 'pid');
    $select->addField('u', 'name', 'username');
    $select->addField('e', 'name');
    $select->addField('e', 'surname');
    $select->addField('e', 'age');
    // Filter only persons named "John".
    $select->condition('e.name', 'John');
    // Filter only persons older than 18 years.
    $select->condition('e.age', 18, '>');
    // Make sure we only get items 0-49, for scalability reasons.
    $select->range(0, 50);
    // Now, loop all these entries and show them in a table. Note that there is no
    // db_fetch_* object or array function being called here. Also note that the
    // following line could have been written as
    // $entries = $select->execute()->fetchAll() which would return each selected
    // record as an object instead of an array.
    $entries = $select->execute()
        ->fetchAll(PDO::FETCH_ASSOC);
    if (!empty($entries)) {
        $rows = array();
        foreach ($entries as $entry) {
            // Sanitize the data before handing it off to the theme layer.
            $rows[] = array_map('check_plain', $entry);
        }
        // Make a table for them.
        $header = array(
            t('Id'),
            t('Created by'),
            t('Name'),
            t('Surname'),
            t('Age'),
        );
        $output .= theme('table', array(
            'header' => $header,
            'rows' => $rows,
        ));
    }
    else {
        drupal_set_message(t('No entries meet the filter criteria (Name = "John" and Age > 18).'));
    }
    return $output;
}