From afe2160e1b8ed46533ab284bad6c1c23b4a7559a Mon Sep 17 00:00:00 2001
From: Yuya Ebihara <ebyhry@gmail.com>
Date: Mon, 5 Dec 2022 21:12:41 +0900
Subject: [PATCH] Fix NPE when column name contains uppercase in MongoDB query
 function

---
 .../java/io/trino/plugin/mongodb/MongoMetadata.java  |  2 +-
 .../trino/plugin/mongodb/TestMongoConnectorTest.java | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/plugin/trino-mongodb/src/main/java/io/trino/plugin/mongodb/MongoMetadata.java b/plugin/trino-mongodb/src/main/java/io/trino/plugin/mongodb/MongoMetadata.java
index 6b91ac588616..a49830247ad0 100644
--- a/plugin/trino-mongodb/src/main/java/io/trino/plugin/mongodb/MongoMetadata.java
+++ b/plugin/trino-mongodb/src/main/java/io/trino/plugin/mongodb/MongoMetadata.java
@@ -168,7 +168,7 @@ public Map<String, ColumnHandle> getColumnHandles(ConnectorSession session, Conn
 
         ImmutableMap.Builder<String, ColumnHandle> columnHandles = ImmutableMap.builder();
         for (MongoColumnHandle columnHandle : columns) {
-            columnHandles.put(columnHandle.getName(), columnHandle);
+            columnHandles.put(columnHandle.getName().toLowerCase(ENGLISH), columnHandle);
         }
         return columnHandles.buildOrThrow();
     }
diff --git a/plugin/trino-mongodb/src/test/java/io/trino/plugin/mongodb/TestMongoConnectorTest.java b/plugin/trino-mongodb/src/test/java/io/trino/plugin/mongodb/TestMongoConnectorTest.java
index c655cc831c30..da556e121bf0 100644
--- a/plugin/trino-mongodb/src/test/java/io/trino/plugin/mongodb/TestMongoConnectorTest.java
+++ b/plugin/trino-mongodb/src/test/java/io/trino/plugin/mongodb/TestMongoConnectorTest.java
@@ -782,6 +782,18 @@ public void testNativeQueryProjection()
                 .matches("SELECT name FROM region");
     }
 
+    @Test
+    public void testNativeQueryCaseNonLowercaseColumn()
+    {
+        String tableName = "test_non_lowercase_column" + randomNameSuffix();
+        client.getDatabase("test").getCollection(tableName)
+                .insertOne(new Document("TestColumn", 1));
+
+        assertQuery(
+                "SELECT * FROM TABLE(mongodb.system.query(database => 'test', collection => '" + tableName + "', filter => '{\"TestColumn\": 1}'))",
+                "VALUES 1");
+    }
+
     @Test
     public void testNativeQueryInvalidArgument()
     {