From 9175755303348f4e656752d3247043558201a92b Mon Sep 17 00:00:00 2001
From: Sergei Morozov <morozov@tut.by>
Date: Wed, 3 Aug 2016 18:02:02 +0300
Subject: [PATCH] Process LIMIT and OFFSET individually by using >= and <=
 instead of BETWEEN

---
 lib/Doctrine/DBAL/Platforms/DB2Platform.php         | 13 ++++++++++---
 .../Tests/DBAL/Functional/ModifyLimitQueryTest.php  | 10 ++++++++++
 .../Tests/DBAL/Platforms/DB2PlatformTest.php        |  8 ++++----
 3 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/lib/Doctrine/DBAL/Platforms/DB2Platform.php b/lib/Doctrine/DBAL/Platforms/DB2Platform.php
index c74e3c11c86..a958b306d85 100644
--- a/lib/Doctrine/DBAL/Platforms/DB2Platform.php
+++ b/lib/Doctrine/DBAL/Platforms/DB2Platform.php
@@ -775,12 +775,19 @@ protected function doModifyLimitQuery($query, $limit, $offset = null)
             return $query;
         }
 
-        $limit = (int) $limit;
-        $offset = (int) (($offset)?:0);
+        $where = array();
+
+        if ($offset !== null) {
+            $where[] = 'db22.DC_ROWNUM >= ' . ($offset + 1);
+        }
+
+        if ($limit !== null) {
+            $where[] = 'db22.DC_ROWNUM <= ' . (($offset ?: 0) + $limit);
+        }
 
         // Todo OVER() needs ORDER BY data!
         $sql = 'SELECT db22.* FROM (SELECT db21.*, ROW_NUMBER() OVER() AS DC_ROWNUM '.
-               'FROM (' . $query . ') db21) db22 WHERE db22.DC_ROWNUM BETWEEN ' . ($offset+1) .' AND ' . ($offset+$limit);
+            'FROM (' . $query . ') db21) db22 WHERE ' . implode(' AND ', $where);
 
         return $sql;
     }
diff --git a/tests/Doctrine/Tests/DBAL/Functional/ModifyLimitQueryTest.php b/tests/Doctrine/Tests/DBAL/Functional/ModifyLimitQueryTest.php
index 0361d696d9b..58ff7e2757e 100644
--- a/tests/Doctrine/Tests/DBAL/Functional/ModifyLimitQueryTest.php
+++ b/tests/Doctrine/Tests/DBAL/Functional/ModifyLimitQueryTest.php
@@ -144,6 +144,16 @@ public function testModifyLimitQueryLineBreaks()
         $this->assertLimitResult(array(2), $sql, 1, 1);
     }
 
+    public function testModifyLimitQueryZeroOffsetNoLimit()
+    {
+        $this->_conn->insert('modify_limit_table', array('test_int' => 1));
+        $this->_conn->insert('modify_limit_table', array('test_int' => 2));
+
+        $sql = "SELECT test_int FROM modify_limit_table ORDER BY test_int ASC";
+
+        $this->assertLimitResult(array(1, 2), $sql, null, 0);
+    }
+
     public function assertLimitResult($expectedResults, $sql, $limit, $offset, $deterministic = true)
     {
         $p = $this->_conn->getDatabasePlatform();
diff --git a/tests/Doctrine/Tests/DBAL/Platforms/DB2PlatformTest.php b/tests/Doctrine/Tests/DBAL/Platforms/DB2PlatformTest.php
index e8b8916539a..1d5c63313f3 100644
--- a/tests/Doctrine/Tests/DBAL/Platforms/DB2PlatformTest.php
+++ b/tests/Doctrine/Tests/DBAL/Platforms/DB2PlatformTest.php
@@ -358,21 +358,21 @@ public function testModifiesLimitQuery()
         );
 
         $this->assertEquals(
-            'SELECT db22.* FROM (SELECT db21.*, ROW_NUMBER() OVER() AS DC_ROWNUM FROM (SELECT * FROM user) db21) db22 WHERE db22.DC_ROWNUM BETWEEN 1 AND 10',
+            'SELECT db22.* FROM (SELECT db21.*, ROW_NUMBER() OVER() AS DC_ROWNUM FROM (SELECT * FROM user) db21) db22 WHERE db22.DC_ROWNUM >= 1 AND db22.DC_ROWNUM <= 10',
             $this->_platform->modifyLimitQuery('SELECT * FROM user', 10, 0)
         );
 
         $this->assertEquals(
-            'SELECT db22.* FROM (SELECT db21.*, ROW_NUMBER() OVER() AS DC_ROWNUM FROM (SELECT * FROM user) db21) db22 WHERE db22.DC_ROWNUM BETWEEN 1 AND 10',
+            'SELECT db22.* FROM (SELECT db21.*, ROW_NUMBER() OVER() AS DC_ROWNUM FROM (SELECT * FROM user) db21) db22 WHERE db22.DC_ROWNUM <= 10',
             $this->_platform->modifyLimitQuery('SELECT * FROM user', 10)
         );
 
         $this->assertEquals(
-            'SELECT db22.* FROM (SELECT db21.*, ROW_NUMBER() OVER() AS DC_ROWNUM FROM (SELECT * FROM user) db21) db22 WHERE db22.DC_ROWNUM BETWEEN 6 AND 15',
+            'SELECT db22.* FROM (SELECT db21.*, ROW_NUMBER() OVER() AS DC_ROWNUM FROM (SELECT * FROM user) db21) db22 WHERE db22.DC_ROWNUM >= 6 AND db22.DC_ROWNUM <= 15',
             $this->_platform->modifyLimitQuery('SELECT * FROM user', 10, 5)
         );
         $this->assertEquals(
-            'SELECT db22.* FROM (SELECT db21.*, ROW_NUMBER() OVER() AS DC_ROWNUM FROM (SELECT * FROM user) db21) db22 WHERE db22.DC_ROWNUM BETWEEN 6 AND 5',
+            'SELECT db22.* FROM (SELECT db21.*, ROW_NUMBER() OVER() AS DC_ROWNUM FROM (SELECT * FROM user) db21) db22 WHERE db22.DC_ROWNUM >= 6 AND db22.DC_ROWNUM <= 5',
             $this->_platform->modifyLimitQuery('SELECT * FROM user', 0, 5)
         );
     }