Merge pull request #2463 from morozov/db2-offset-no-limit

IBM_DB2 platform doesn't handle offset without limit

lib/Doctrine/DBAL/Platforms/DB2Platform.php

@@ -771,18 +771,26 @@ class DB2Platform extends AbstractPlatform
      */
     protected function doModifyLimitQuery($query, $limit, $offset = null)
     {
-        if ($limit === null && $offset === null) {
-            return $query;
+        $where = array();
+
+        if ($offset > 0) {
+            $where[] = sprintf('db22.DC_ROWNUM >= %d', $offset + 1);
         }
 
-        $limit = (int) $limit;
-        $offset = (int) (($offset)?:0);
+        if ($limit !== null) {
+            $where[] = sprintf('db22.DC_ROWNUM <= %d', $offset + $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);
+        if (empty($where)) {
+            return $query;
+        }
 
-        return $sql;
+        // Todo OVER() needs ORDER BY data!
+        return sprintf(
+            'SELECT db22.* FROM (SELECT db21.*, ROW_NUMBER() OVER() AS DC_ROWNUM FROM (%s) db21) db22 WHERE %s',
+            $query,
+            implode(' AND ', $where)
+        );
     }
 
     /**

tests/Doctrine/Tests/DBAL/Functional/ModifyLimitQueryTest.php

@@ -145,6 +145,16 @@ SQL;
         $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();

tests/Doctrine/Tests/DBAL/Platforms/DB2PlatformTest.php

@@ -358,21 +358,21 @@ class DB2PlatformTest extends AbstractPlatformTestCase
         );
 
         $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, 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)
         );
     }