Question

My situation may be a bit abnormal, but I have foreign keys defined in my MySQL database, while enforcing referential integrity in the Zend_Db_Table classes. The tables use the InnoDB storage engine.

When deleting a record, the Zend Framework will properly identify immediate children via the $_referenceMap in the table model and delete them. However, if there are any children of the immediate child, I am getting an error back from the database about violating the referential integrity of that foreign key: SQLSTATE[23000]: Integrity constraint violation: 1451 Cannot delete or update a parent row: a foreign key constraint fails. It seems that the Zend_Db_Table_Abstract doesn’t enforce referential integrity in a recursive fashion.

Has anyone else encountered this? Is it a Zend Framework bug? Workarounds? Fixes?

---

UPDATE

Nearly a week later and I have no replies to this question. I am thinking I’ll have to extend the Zend_Db_Table_Row_Abstract class myself to accomplish this.

Answer 1

I ended up extending the Zend_Db_Table_Abstract class to accomplish this. The _cascadeDelete public function makes a call to the database adapter delete function. I made changes so that the delete function from Zend_Db_Table_Row_Abstract gets called instead. This makes record deletions recursive.

UPDATE: I have added code for when on delete is set to self::SET_NULL.

Here’s my modified version of _cascadeDelete:

/**
 * Called by parent table's class during delete() method.
 *
 * @param  string $parentTableClassname
 * @param  array  $primaryKey
 * @return int    Number of affected rows
 */
public function _cascadeDelete($parentTableClassname, array $primaryKey)
{
    $this->_setupMetadata();
    $rowsAffected = 0;
    foreach ($this->_getReferenceMapNormalized() as $map) {
        if ($map[self::REF_TABLE_CLASS] == $parentTableClassname && isset($map[self::ON_DELETE])) {
            switch ($map[self::ON_DELETE]) {
                case self::CASCADE:
                    $select = $this->select();
                    for ($i = 0; $i < count($map[self::COLUMNS]); ++$i) {
                        $col = $this->_db->foldCase($map[self::COLUMNS][$i]);
                        $refCol = $this->_db->foldCase($map[self::REF_COLUMNS][$i]);
                        $type = $this->_metadata[$col]['DATA_TYPE'];
                        $select->where($this->_db->quoteIdentifier($col, true) . ' = ?',
                            $primaryKey[$refCol], $type);
                    }
                    $rows = $this->fetchAll($select);
                    $rowsAffected += count($rows);
                    foreach ($rows as $row) {
                        $row->delete();
                    }
                    break;
                case self::SET_NULL: {
                    $update = array();
                    $where = array();
                    for ($i = 0; $i < count($map[self::COLUMNS]); ++$i) {
                        $col = $this->_db->foldCase($map[self::COLUMNS][$i]);
                        $refCol = $this->_db->foldCase($map[self::REF_COLUMNS][$i]);
                        $type = $this->_metadata[$col]['DATA_TYPE'];
                        $update[$col] = null;
                        $where[] = $this->_db->quoteInto(
                            $this->_db->quoteIdentifier($col, true) . ' = ?',
                            $primaryKey[$refCol], $type);
                    }
                    $rowsAffected += $this->update($update, $where);
                    break;
                }
                default:
                    // no action
                    break;
            }
        }
    }
    return $rowsAffected;
}