protected function findConstraints($table)
{
$tableName = $this->quoteValue($table->name);
$tableSchema = $this->quoteValue($table->schemaName);
//We need to extract the constraints de hard way since:
//http://www.postgresql.org/message-id/[email protected]
$sql = <<<SQL
select
ct.conname as constraint_name,
a.attname as column_name,
fc.relname as foreign_table_name,
fns.nspname as foreign_table_schema,
fa.attname as foreign_column_name
from
(SELECT ct.conname, ct.conrelid, ct.confrelid, ct.conkey, ct.contype, ct.confkey, generate_subscripts(ct.conkey, 1) AS s
FROM pg_constraint ct
) AS ct
inner join pg_class c on c.oid=ct.conrelid
inner join pg_namespace ns on c.relnamespace=ns.oid
inner join pg_attribute a on a.attrelid=ct.conrelid and a.attnum = ct.conkey[ct.s]
left join pg_class fc on fc.oid=ct.confrelid
left join pg_namespace fns on fc.relnamespace=fns.oid
left join pg_attribute fa on fa.attrelid=ct.confrelid and fa.attnum = ct.confkey[ct.s]
where
ct.contype='f'
and c.relname={$tableName}
and ns.nspname={$tableSchema}
order by
fns.nspname, fc.relname, a.attnum
SQL;
$constraints = [];
foreach ($this->db->createCommand($sql)->queryAll() as $constraint) {
if ($constraint['foreign_table_schema'] !== $this->defaultSchema) {
$foreignTable = $constraint['foreign_table_schema'] . '.' . $constraint['foreign_table_name'];
} else {
$foreignTable = $constraint['foreign_table_name'];
}
$name = $constraint['constraint_name'];
if (!isset($constraints[$name])) {
$constraints[$name] = ['tableName' => $foreignTable, 'columns' => []];
}
$constraints[$name]['columns'][$constraint['column_name']] = $constraint['foreign_column_name'];
}
foreach ($constraints as $constraint) {
$table->foreignKeys[] = array_merge([$constraint['tableName']], $constraint['columns']);
}
}
