From d61b3d02695a7eb38c8a6fe99ec0c278910f1017 Mon Sep 17 00:00:00 2001
From: Eloy Lafuente <stronk7@moodle.org>
Date: Wed, 17 Mar 2010 01:34:29 +0000
Subject: [PATCH] MDL-21834 DDL tests - fix concurrent temp tables for mssql +
 1 incorrect test

---
 lib/ddl/mssql_sql_generator.php | 23 +++++++++++++++++++++++
 lib/ddl/simpletest/testddl.php  |  2 +-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/lib/ddl/mssql_sql_generator.php b/lib/ddl/mssql_sql_generator.php
index e5dbcfcc936..4dfdaa93e02 100644
--- a/lib/ddl/mssql_sql_generator.php
+++ b/lib/ddl/mssql_sql_generator.php
@@ -557,6 +557,29 @@ class mssql_sql_generator extends sql_generator {
         return $results;
     }
 
+    /**
+     * Given three strings (table name, list of fields (comma separated) and suffix),
+     * create the proper object name quoting it if necessary.
+     *
+     * IMPORTANT: This function must be used to CALCULATE NAMES of objects TO BE CREATED,
+     *            NEVER TO GUESS NAMES of EXISTING objects!!!
+     *
+     * IMPORTANT: We are overriding this function for the MSSQL generator because objects
+     * belonging to temporary tables aren't searchable in the catalog neither in information
+     * schema tables. So, for temporary tables, we are going to add 4 randomly named "virtual"
+     * fields, so the generated names won't cause concurrency problems. Really nasty hack,
+     * but the alternative involves modifying all the creation table code to avoid naming
+     * constraints for temp objects and that will dupe a lot of code.
+     *
+     */
+    public function getNameForObject($tablename, $fields, $suffix='') {
+        if ($this->temptables->is_temptable($tablename)) { // Is temp table, inject random field names
+            $random = strtolower(random_string(12)); // 12cc to be split in 4 parts
+            $fields = $fields . ', ' . implode(', ', str_split($random, 3));
+        }
+        return parent::getNameForObject($tablename, $fields, $suffix); // Delegate to parent (common) algorithm
+    }
+
     /**
      * Given one object name and it's type (pk, uk, fk, ck, ix, uix, seq, trg)
      * return if such name is currently in use (true) or no (false)
diff --git a/lib/ddl/simpletest/testddl.php b/lib/ddl/simpletest/testddl.php
index 2126586d444..d4b7500e64f 100755
--- a/lib/ddl/simpletest/testddl.php
+++ b/lib/ddl/simpletest/testddl.php
@@ -1294,7 +1294,7 @@ class ddl_test extends UnitTestCase {
         // Try to create table with same name, must throw exception
         $dupetable = $this->tables['test_table0'];
         try {
-            $dbman->create_temp_table($dupetable);
+            $dbman->create_table($dupetable);
             $this->assertTrue(false);
         } catch (Exception $e) {
             $this->assertTrue($e instanceof ddl_exception);