/**
* @todo should *all* sequences be dropped in stage3, rather than just the shim?
* the only reason we don't is because pgsql8 drops in stage 1...
*/
public static function diff_sequences($ofs1, $ofs3, $old_schema, $new_schema)
{
$new_sequences = static::get_sequences($new_schema);
if ($old_schema != null) {
$old_sequences = static::get_sequences($old_schema);
} else {
$old_sequences = array();
}
if (empty($new_sequences)) {
// there are no sequences in the new schema, so if there used to be sequences,
// we can just drop the whole shim table
if (!empty($old_sequences)) {
$ofs3->write(mysql5_sequence::get_shim_drop_sql());
}
} else {
// there *are* sequences in the new schema, so if there didn't used to be,
// we need to add the shim in before adding any sequences
if (empty($old_sequences)) {
$ofs1->write(mysql5_sequence::get_shim_creation_sql() . "\n\n");
$ofs1->write(mysql5_sequence::get_creation_sql($new_schema, $new_sequences) . "\n");
} else {
// there were schemas in the old schema
$common_sequences = array();
// only drop sequences not in the new schema
$to_drop = array();
foreach ($old_sequences as $old_seq) {
if (static::schema_contains_sequence($new_schema, $old_seq['name'], true)) {
// if the sequence *is* in the new schema, then it might have changed
$common_sequences[(string) $old_seq['name']] = $old_seq;
} else {
$to_drop[] = $old_seq;
}
}
if (!empty($to_drop)) {
$ofs1->write(mysql5_sequence::get_drop_sql($old_schema, $to_drop) . "\n\n");
}
// only add sequences not in the old schema
$to_insert = array();
foreach ($new_sequences as $new_seq) {
if (static::schema_contains_sequence($old_schema, $new_seq['name'])) {
// there used to be a sequence named $new_seq['name']
self::diff_single($ofs1, $common_sequences[(string) $new_seq['name']], $new_seq);
} elseif (!dbsteward::$ignore_oldnames && !empty($new_seq['oldSequenceName']) && static::schema_contains_sequence($old_schema, $new_seq['oldSequenceName'])) {
// there used to be a sequence named $new_seq['oldSequenceName']
self::diff_single($ofs1, $common_sequences[(string) $new_seq['oldSequenceName']], $new_seq);
} else {
$to_insert[] = $new_seq;
}
}
if (!empty($to_insert)) {
$ofs1->write(mysql5_sequence::get_creation_sql($new_schema, $to_insert) . "\n");
}
}
}
}
private function setup_shim()
{
$this->pdo->exec($sql = mysql5_sequence::get_shim_drop_sql());
// echo $sql . "\n\n";
$this->pdo->exec($sql = mysql5_sequence::get_shim_creation_sql());
// echo $sql . "\n\n";
}
