MySQL-server-version für den richtigen syntax zur Verwendung in der Nähe

Ich erhalte die folgende Fehlermeldung:

"Error: You have an error in your SQL syntax; check the manual that corresponds
to your MySQL server version for the right syntax to use near ' `DeweyEdition`
BLOB NOT NULL, , `DeweyNumber` BLOB NOT NULL)' at line 1
<br />Error No: 1064<br />ALTER TABLE tt_hj_import ADD COLUMN
(`CountryOfPub` BLOB NOT NULL, , `DeweyEdition` BLOB NOT NULL, ,
`DeweyNumber` BLOB NOT NULL) in /var/www/system/database/mysql.php on line 50" 

Mein code:

public function alterImportTable($new_fields) {
    if (!empty($new_fields)) {
        $sql = "ALTER TABLE " . DB_PREFIX . "hj_import ADD COLUMN ";
        $fields_sql = array();
        foreach ($new_fields as $field) {
            $fields_sql[] = '`' . $field . "` BLOB NOT NULL, ";
        }
        $sql .= '(' . implode(', ', $fields_sql) . ')';
        $sql = str_replace(', )', ')', $sql);
        $this->db->query($sql);
    }
}

Wie kann ich dieses Problem beheben?

InformationsquelleAutor user2496631 | 2013-11-25