Orderby new features (#744)

* Update README.md

* added secondary param to orderby relation

README.md

@@ -760,6 +760,18 @@ ORDER BY posts.title
 ...
 ```
 
+`http://prettus.local/users?orderBy=posts:custom_id,other_id|posts.title&sortedBy=desc`
+
+Query will have something like this
+
+```sql
+...
+INNER JOIN posts ON users.custom_id = posts.other_id
+...
+ORDER BY posts.title
+...
+```
+
 Sorting multiple columns same sortedBy
 
 `http://prettus.local/users?orderBy=name;created_at&sortedBy=desc`

src/Prettus/Repository/Criteria/RequestCriteria.php

@@ -190,9 +190,16 @@ protected function parserFieldsOrderBy($model, $orderBy, $sortedBy)
             $sortColumn = $split[1];
 
             $split = explode(':', $sortTable);
-            if(count($split) > 1) {
+            $localKey = '.id';
+            if (count($split) > 1) {
                 $sortTable = $split[0];
+
+                $commaExp = explode(',', $split[1]);
                 $keyName = $table.'.'.$split[1];
+                if (count($commaExp) > 1) {
+                    $keyName = $table.'.'.$commaExp[0];
+                    $localKey = '.'.$commaExp[1];
+                }
             } else {
                 /*
                  * If you do not define which column to use as a joining column on current table, it will
@@ -206,7 +213,7 @@ protected function parserFieldsOrderBy($model, $orderBy, $sortedBy)
             }
 
             $model = $model
-                ->leftJoin($sortTable, $keyName, '=', $sortTable.'.id')
+                ->leftJoin($sortTable, $keyName, '=', $sortTable.$localKey)
                 ->orderBy($sortColumn, $sortedBy)
                 ->addSelect($table.'.*');
         } else {