From 4ca6ed046a31c8fc08a4b74debb9983f24c33757 Mon Sep 17 00:00:00 2001
From: sarahkemp <thesarahkemp@gmail.com>
Date: Tue, 29 Dec 2020 11:01:22 -0800
Subject: [PATCH 1/2] Add $offsetCompatibilityMode to DB2Grammar

---
 src/Database/Query/Grammars/DB2Grammar.php | 30 ++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/src/Database/Query/Grammars/DB2Grammar.php b/src/Database/Query/Grammars/DB2Grammar.php
index 1d119f0..fb1ee6e 100644
--- a/src/Database/Query/Grammars/DB2Grammar.php
+++ b/src/Database/Query/Grammars/DB2Grammar.php
@@ -19,6 +19,12 @@ class DB2Grammar extends Grammar
      */
     protected $dateFormat;
 
+    /**
+     * Offset compatibility mode true triggers FETCH FIRST X ROWS and ROW_NUM behavior for older versions of DB2
+     * @var bool
+     */
+    protected $offsetCompatibilityMode = true;
+
     /**
      * Wrap a single string in keyword identifiers.
      *
@@ -45,7 +51,10 @@ protected function wrapValue($value)
      */
     protected function compileLimit(Builder $query, $limit)
     {
-        return "FETCH FIRST $limit ROWS ONLY";
+        if($this->offsetCompatibilityMode){
+            return "FETCH FIRST $limit ROWS ONLY";
+        }
+        return parent::compileLimit($query, $limit);
     }
 
     /**
@@ -57,6 +66,10 @@ protected function compileLimit(Builder $query, $limit)
      */
     public function compileSelect(Builder $query)
     {
+        if(!$this->offsetCompatibilityMode){
+            return parent::compileSelect($query);
+        }
+
         if (is_null($query->columns)) {
             $query->columns = ['*'];
         }
@@ -183,7 +196,10 @@ protected function compileTableExpression($sql, $constraint)
      */
     protected function compileOffset(Builder $query, $offset)
     {
-        return '';
+        if($this->offsetCompatibilityMode){
+            return '';
+        }
+        return parent::compileOffset($query, $offset);
     }
 
     /**
@@ -221,6 +237,16 @@ public function setDateFormat($dateFormat)
         $this->dateFormat = $dateFormat;
     }
 
+    /**
+     * Set offset compatibility mode to trigger FETCH FIRST X ROWS and ROW_NUM behavior for older versions of DB2
+     *
+     * @param $bool
+     */
+    public function setOffsetCompatibilityMode($bool)
+    {
+        $this->offsetCompatibilityMode = $bool;
+    }
+
     /**
      * Compile the SQL statement to define a savepoint.
      *

From 1ee2072af42ba5b6c8d94eaeb44527da051896ce Mon Sep 17 00:00:00 2001
From: sarahkemp <thesarahkemp@gmail.com>
Date: Tue, 29 Dec 2020 11:02:21 -0800
Subject: [PATCH 2/2] Pull offset_compatibility_mode from options

---
 src/Database/DB2Connection.php | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/Database/DB2Connection.php b/src/Database/DB2Connection.php
index 3899d02..4cf4dfb 100644
--- a/src/Database/DB2Connection.php
+++ b/src/Database/DB2Connection.php
@@ -108,6 +108,10 @@ protected function getDefaultQueryGrammar()
             $defaultGrammar->setDateFormat($this->config['date_format']);
         }
 
+        if (array_key_exists('offset_compatibility_mode', $this->config)) {
+            $defaultGrammar->setOffsetCompatibilityMode($this->config['offset_compatibility_mode']);
+        }
+
         return $this->withTablePrefix($defaultGrammar);
     }