/**
* drop existing constraint
*
* @param string $table name of table that should be used in method
* @param string $name name of the constraint to be dropped
* @param string $primary hint if the constraint is primary
*
* @return mixed MDB2_OK on success, a MDB2 error on failure
* @access public
*/
function dropConstraint($table, $name, $primary = false)
{
$db = $this->getDBInstance();
if (MDB2::isError($db)) {
return $db;
}
// is it an UNIQUE index?
$query = 'SELECT relname
FROM pg_class
WHERE oid IN (
SELECT indexrelid
FROM pg_index, pg_class
WHERE pg_class.relname = ' . $db->quote($table, 'text') . '
AND pg_class.oid = pg_index.indrelid
AND indisunique = \'t\')
EXCEPT
SELECT conname
FROM pg_constraint, pg_class
WHERE pg_constraint.conrelid = pg_class.oid
AND relname = ' . $db->quote($table, 'text');
$unique = $db->queryCol($query, 'text');
if (MDB2::isError($unique) || empty($unique)) {
// not an UNIQUE index, maybe a CONSTRAINT
return parent::dropConstraint($table, $name, $primary);
}
if (in_array($name, $unique)) {
$result = $db->exec('DROP INDEX ' . $db->quoteIdentifier($name, true));
if (MDB2::isError($result)) {
return $result;
}
return MDB2_OK;
}
$idxname = $db->getIndexName($name);
if (in_array($idxname, $unique)) {
$result = $db->exec('DROP INDEX ' . $db->quoteIdentifier($idxname, true));
if (MDB2::isError($result)) {
return $result;
}
return MDB2_OK;
}
return $db->raiseError(MDB2_ERROR_NOT_FOUND, null, null, $name . ' is not an existing constraint for table ' . $table, __FUNCTION__);
}
/**
* drop existing constraint
*
* @param string $table name of table that should be used in method
* @param string $name name of the constraint to be dropped
* @param string $primary hint if the constraint is primary
* @return mixed MDB2_OK on success, a MDB2 error on failure
* @access public
*/
function dropConstraint($table, $name, $primary = false)
{
$db = $this->getDBInstance();
if (PEAR::isError($db)) {
return $db;
}
//is it a FK constraint? If so, also delete the associated triggers
$db->loadModule('Reverse', null, true);
$definition = $db->reverse->getTableConstraintDefinition($table, $name);
if (!PEAR::isError($definition) && !empty($definition['foreign'])) {
//first drop the FK enforcing triggers
$result = $this->_dropFKTriggers($table, $name, $definition['references']['table']);
if (PEAR::isError($result)) {
return $result;
}
}
return parent::dropConstraint($table, $name, $primary);
}
