From 350db41f5e8b8fba0d01543454f33870e1866b76 Mon Sep 17 00:00:00 2001
From: TAQI RAZA <tqi.rza@gmail.com>
Date: Mon, 12 Oct 2026 00:00:53 +0000
Subject: [PATCH] fix: resolve #1659 - Support ANSI SQL null semantics and
 evaluation for IN clause

---
 dozer-sql/expression/src/in_list.rs       | 11 +++++++-
 dozer-sql/src/expression/tests/in_list.rs | 32 +++++++++++++++++++++++
 2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/dozer-sql/expression/src/in_list.rs b/dozer-sql/expression/src/in_list.rs
index d538214d65..3bb0009823 100644
--- a/dozer-sql/expression/src/in_list.rs
+++ b/dozer-sql/expression/src/in_list.rs
@@ -12,14 +12,23 @@ pub(crate) fn evaluate_in_list(
     record: &Record,
 ) -> Result<Field, Error> {
     let field = expr.evaluate(record, schema)?;
+    if field == Field::Null {
+        return Ok(Field::Null);
+    }
     let mut result = false;
+    let mut has_null = false;
     for item in list {
         let item = item.evaluate(record, schema)?;
-        if field == item {
+        if item == Field::Null {
+            has_null = true;
+        } else if field == item {
             result = true;
             break;
         }
     }
+    if !result && has_null {
+        return Ok(Field::Null);
+    }
     // Negate the result if the IN list was negated.
     if negated {
         result = !result;
diff --git a/dozer-sql/src/expression/tests/in_list.rs b/dozer-sql/src/expression/tests/in_list.rs
index 0296f2210c..52cedbe1be 100644
--- a/dozer-sql/src/expression/tests/in_list.rs
+++ b/dozer-sql/src/expression/tests/in_list.rs
@@ -84,3 +84,35 @@ fn test_not_in_list() {
     );
     assert_eq!(f, Field::Boolean(false));
 }
+
+
+#[test]
+fn test_in_list_null_semantics() {
+    let f = run_fct(
+        "SELECT NULL IN (1, 2, 3)",
+        Schema::default(),
+        vec![],
+    );
+    assert_eq!(f, Field::Null);
+
+    let f = run_fct(
+        "SELECT 42 IN (1, 2, NULL)",
+        Schema::default(),
+        vec![],
+    );
+    assert_eq!(f, Field::Null);
+
+    let f = run_fct(
+        "SELECT 42 NOT IN (1, 2, NULL)",
+        Schema::default(),
+        vec![],
+    );
+    assert_eq!(f, Field::Null);
+
+    let f = run_fct(
+        "SELECT 42 IN (1, 2, 42, NULL)",
+        Schema::default(),
+        vec![],
+    );
+    assert_eq!(f, Field::Boolean(true));
+}