From 8583898395836c101ff0cfcd4e11b55c81075b18 Mon Sep 17 00:00:00 2001
From: nomiero <hunomie@microsoft.com>
Date: Wed, 22 May 2019 08:45:44 -0700
Subject: [PATCH] Fix null value query regression

---
 .../microsoft/azure/cosmosdb/spark/schema/FilterConverter.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/scala/com/microsoft/azure/cosmosdb/spark/schema/FilterConverter.scala b/src/main/scala/com/microsoft/azure/cosmosdb/spark/schema/FilterConverter.scala
index a2943988..a863953a 100644
--- a/src/main/scala/com/microsoft/azure/cosmosdb/spark/schema/FilterConverter.scala
+++ b/src/main/scala/com/microsoft/azure/cosmosdb/spark/schema/FilterConverter.scala
@@ -54,7 +54,7 @@ private [spark] object FilterConverter extends CosmosDBLoggingTrait {
         case In(field, values)                => s"""(c${createFieldIdentifier(field)} IN (${values.map(value => createValueClause(value)).mkString(",")}))"""
         case LessThan(field, value)           => s"""(c${createFieldIdentifier(field)} < ${createValueClause(value)})"""
         case LessThanOrEqual(field, value)    => s"""(c${createFieldIdentifier(field)} <= ${createValueClause(value)})"""
-        case IsNull(field)                    => s"""(c${createFieldIdentifier(field)} = null"""
+        case IsNull(field)                    => s"""(c${createFieldIdentifier(field)} = null)"""
         case IsNotNull(field)                 => s"""(c${createFieldIdentifier(field)} != null)"""
         case And(leftFilter, rightFilter)     => s"""(${createWhereClause(Array(leftFilter))} AND ${createWhereClause(Array(rightFilter))})"""
         case Or(leftFilter, rightFilter)      => s"""(${createWhereClause(Array(leftFilter))} OR ${createWhereClause(Array(rightFilter))})"""