relations

[m6w6/pq-gateway] / lib / pq / Gateway / Table / Relations.php

diff --git a/lib/pq/Gateway/Table/Relations.php b/lib/pq/Gateway/Table/Relations.php
new file mode 100644 (file)
index 0000000..0f946fa
--- /dev/null
+++ b/lib/pq/Gateway/Table/Relations.php
@@ -0,0 +1,59 @@
+<?php
+
+namespace pq\Gateway\Table;
+
+use \pq\Gateway\Table;
+
+const RELATION_SQL = <<<SQL
+select
+        substring(att1.attname from '^.*(?=_'||att2.attname||'$)') as "id"
+       ,cl1.relname                                                as "foreignTable"
+    ,att1.attname                                               as "foreignColumn"
+       ,cl2.relname                                                as "referencedTable"
+    ,att2.attname                                               as "referencedColumn"
+from
+     pg_constraint co
+    ,pg_class      cl2
+    ,pg_class      cl1
+    ,pg_attribute  att2
+    ,pg_attribute  att1
+where
+       (       cl1.relname = \$1
+       or      cl2.relname = \$1)
+and co.confrelid != 0
+and co.confrelid  = cl2.oid
+and co.conrelid   = cl1.oid
+and co.confkey[1] = att2.attnum and cl2.oid = att2.attrelid
+and co.conkey[1]  = att1.attnum and cl1.oid = att1.attrelid
+order by 
+        cl1.relname
+       ,att1.attnum
+SQL;
+
+class Relations
+{
+       public $references;
+       
+       function __construct(Table $table) {
+               // FIXME cache
+               $this->references = $table->getConnection()
+                       ->execParams(RELATION_SQL, array($table->getName()))
+                       ->map(array(0,1), array(2,3,4), \pq\Result::FETCH_OBJECT);
+       }
+       
+       function __isset($r) {
+               return isset($this->references->$r);
+       }
+       
+       function __get($r) {
+               return $this->references->$r;
+       }
+       
+       function __set($r, $v) {
+               $this->references->$r = $v;
+       }
+       
+       function __unset($r){
+               unset($this->references->$r);
+       }
+}