From f3700f8cb3ac9c1208c4fa8a9de8326296a4632b Mon Sep 17 00:00:00 2001
From: stronk7 <stronk7>
Date: Thu, 26 Jun 2008 18:27:22 +0000
Subject: [PATCH] Adding new sql_null_from_clause() helper function from
 19_STABLE. MDL-13861

---
 lib/dml/moodle_database.php              | 9 +++++++++
 lib/dml/oci8po_adodb_moodle_database.php | 4 ++++
 2 files changed, 13 insertions(+)

diff --git a/lib/dml/moodle_database.php b/lib/dml/moodle_database.php
index ab06ee7226..b4cfe68b70 100644
--- a/lib/dml/moodle_database.php
+++ b/lib/dml/moodle_database.php
@@ -1199,6 +1199,15 @@ abstract class moodle_database {
         return '((' . $int1 . ') ^ (' . $int2 . '))';
     }
 
+    /**
+     * Returns the FROM clause required by some DBs in all SELECT statements
+     * To be used in queries not having FROM clause to provide cross_db
+     * Most DBs don't need it, hence the default is ''
+     */
+    public function sql_null_from_clause() {
+        return '';
+    }
+
     /**
      * Returns the SQL to be used in order to CAST one CHAR column to INTEGER.
      *
diff --git a/lib/dml/oci8po_adodb_moodle_database.php b/lib/dml/oci8po_adodb_moodle_database.php
index bc756f7cc5..52ce5c7d41 100644
--- a/lib/dml/oci8po_adodb_moodle_database.php
+++ b/lib/dml/oci8po_adodb_moodle_database.php
@@ -166,6 +166,10 @@ class oci8po_adodb_moodle_database extends adodb_moodle_database {
         return '((' . $int1 . ') # (' . $int2 . '))';
     }
 
+    function sql_null_from_clause() {
+        return ' FROM dual';
+    }
+
     public function sql_cast_char2int($fieldname, $text=false) {
         if (!$text) {
             return ' CAST(' . $fieldname . ' AS INT) ';
-- 
2.39.5