Fix UUID empty string handling in UPDATE operations

cpp/deeplake_pg/nd_utils.hpp

@@ -662,6 +662,11 @@ inline Datum nd_to_datum(const nd::array& curr_val, Oid attr_typeid, int32_t typ
     }
     case UUIDOID: {
         auto str = base::string_view_cast(base::span_cast<const char>(curr_val.data()));
+        // Treat empty string as NULL for UUID columns (same as duckdb_deeplake_scan.cpp)
+        if (str.empty()) {
+            // Return NULL datum - caller must set is_null flag appropriately
+            return (Datum)0;
+        }
         // CStringGetDatum expects a null-terminated string, hence copy the string
         std::string str_copy(str.data(), str.size());
         Datum uuid = DirectFunctionCall1(uuid_in, CStringGetDatum(str_copy.c_str()));

cpp/deeplake_pg/table_scan_impl.hpp

@@ -115,6 +115,10 @@ inline std::pair<Datum, bool> table_scan::get_datum(int32_t column_number, int64
     }
     case UUIDOID: {
         auto str = table_data_.get_streamers().value<std::string_view>(column_number, row_number);
+        // Treat empty string as NULL for UUID columns (same as duckdb_deeplake_scan.cpp)
+        if (str.empty()) {
+            return {(Datum)0, true};
+        }
         std::string str_copy(str.data(), str.size());
         Datum uuid = DirectFunctionCall1(uuid_in, CStringGetDatum(str_copy.c_str()));
         return {uuid, false};

postgres/tests/py_tests/test_uuid_null_update_bug.py

@@ -0,0 +1,171 @@
+"""
+Test for UUID NULL value bug during UPDATE operations.
+
+Bug: When a table has a UUID column with NULL values and another column (e.g., bool),
+attempting to update the non-UUID column fails with "invalid value for type uuid".
+
+Reproduction steps:
+1. Create table with UUID column and bool column using DEEPLAKE access method
+2. Add rows with NULL UUID values
+3. Update the bool column value
+4. Expected: Update should succeed
+5. Actual: Fails with "invalid value for type uuid"
+"""
+import pytest
+import asyncpg
+from test_utils.assertions import Assertions
+
+
+@pytest.mark.asyncio
+async def test_uuid_null_update_bug(db_conn: asyncpg.Connection):
+    """
+    Test that updating non-UUID columns works when UUID column contains NULL values.
+
+    This reproduces the bug where updating a bool column fails when there's a
+    UUID column with NULL values in the same table.
+    """
+    assertions = Assertions(db_conn)
+
+    try:
+        # Step 1: Create table with UUID and bool columns using DEEPLAKE access method
+        await db_conn.execute("""
+            CREATE TABLE test_uuid_bool (
+                id SERIAL PRIMARY KEY,
+                uuid_col UUID,
+                bool_col BOOL
+            ) USING deeplake
+        """)
+        print("✓ Created table with UUID and bool columns")
+
+        # Step 2: Add rows with NULL/empty values
+        await db_conn.execute("""
+            INSERT INTO test_uuid_bool (uuid_col, bool_col) VALUES
+            (NULL, NULL),
+            (NULL, FALSE),
+            (NULL, TRUE)
+        """)
+        print("✓ Inserted rows with NULL UUID values")
+
+        # Verify initial state
+        rows = await db_conn.fetch("SELECT * FROM test_uuid_bool ORDER BY id")
+        assert len(rows) == 3, f"Expected 3 rows, got {len(rows)}"
+        assert all(row['uuid_col'] is None for row in rows), "All UUID values should be NULL"
+        print(f"✓ Verified initial state: {len(rows)} rows with NULL UUIDs")
+
+        # Step 3: Attempt to update the bool column
+        # This is where the bug occurs - it should succeed but fails with
+        # "invalid value for type uuid"
+        try:
+            await db_conn.execute("""
+                UPDATE test_uuid_bool
+                SET bool_col = TRUE
+                WHERE id = 1
+            """)
+            print("✓ Successfully updated bool column (bug is fixed!)")
+        except Exception as e:
+            print(f"✗ Failed to update bool column: {e}")
+            raise AssertionError(f"Update failed with error: {e}. This is the bug we're testing for.")
+
+        # Verify the update worked
+        row = await db_conn.fetchrow("SELECT * FROM test_uuid_bool WHERE id = 1")
+        assert row['bool_col'] is True, "bool_col should be TRUE after update"
+        assert row['uuid_col'] is None, "uuid_col should still be NULL"
+        print("✓ Update succeeded and values are correct")
+
+        # Test additional update scenarios
+        await db_conn.execute("""
+            UPDATE test_uuid_bool
+            SET bool_col = FALSE
+            WHERE uuid_col IS NULL
+        """)
+        print("✓ Batch update with NULL UUID condition succeeded")
+
+        # Verify all bool values are now FALSE
+        rows = await db_conn.fetch("SELECT * FROM test_uuid_bool ORDER BY id")
+        assert all(row['bool_col'] is False for row in rows), "All bool values should be FALSE"
+        print("✓ Batch update worked correctly")
+
+    finally:
+        # Cleanup
+        await db_conn.execute("DROP TABLE IF EXISTS test_uuid_bool CASCADE")
+
+
+@pytest.mark.asyncio
+async def test_uuid_null_multiple_columns_update(db_conn: asyncpg.Connection):
+    """
+    Test updating multiple different column types when UUID column has NULL values.
+
+    This is a more comprehensive test covering multiple data types.
+    """
+    try:
+        # Create table with UUID and various other column types
+        await db_conn.execute("""
+            CREATE TABLE test_uuid_multi (
+                id SERIAL PRIMARY KEY,
+                uuid_col UUID,
+                bool_col BOOL,
+                int_col INT,
+                text_col TEXT
+            ) USING deeplake
+        """)
+        print("✓ Created table with UUID and multiple column types")
+
+        # Insert rows with NULL UUID values
+        await db_conn.execute("""
+            INSERT INTO test_uuid_multi (uuid_col, bool_col, int_col, text_col) VALUES
+            (NULL, NULL, NULL, NULL),
+            (NULL, TRUE, 42, 'test'),
+            ('550e8400-e29b-41d4-a716-446655440000'::uuid, FALSE, 100, 'with_uuid')
+        """)
+        print("✓ Inserted rows with mixed UUID values (NULL and non-NULL)")
+
+        # Test updating bool column where UUID is NULL
+        await db_conn.execute("""
+            UPDATE test_uuid_multi
+            SET bool_col = TRUE
+            WHERE id = 1
+        """)
+        print("✓ Updated bool column for row with NULL UUID")
+
+        # Test updating int column where UUID is NULL
+        await db_conn.execute("""
+            UPDATE test_uuid_multi
+            SET int_col = 999
+            WHERE id = 1
+        """)
+        print("✓ Updated int column for row with NULL UUID")
+
+        # Test updating text column where UUID is NULL
+        await db_conn.execute("""
+            UPDATE test_uuid_multi
+            SET text_col = 'updated'
+            WHERE id = 1
+        """)
+        print("✓ Updated text column for row with NULL UUID")
+
+        # Test updating multiple columns at once
+        await db_conn.execute("""
+            UPDATE test_uuid_multi
+            SET bool_col = FALSE, int_col = 777, text_col = 'multi_update'
+            WHERE id = 2
+        """)
+        print("✓ Updated multiple columns at once for row with NULL UUID")
+
+        # Verify all updates worked correctly
+        row = await db_conn.fetchrow("SELECT * FROM test_uuid_multi WHERE id = 1")
+        assert row['bool_col'] is True, "bool_col should be TRUE"
+        assert row['int_col'] == 999, "int_col should be 999"
+        assert row['text_col'] == 'updated', "text_col should be 'updated'"
+        assert row['uuid_col'] is None, "uuid_col should still be NULL"
+
+        row = await db_conn.fetchrow("SELECT * FROM test_uuid_multi WHERE id = 2")
+        assert row['bool_col'] is False, "bool_col should be FALSE"
+        assert row['int_col'] == 777, "int_col should be 777"
+        assert row['text_col'] == 'multi_update', "text_col should be 'multi_update'"
+        assert row['uuid_col'] is None, "uuid_col should still be NULL"
+
+        print("✓ All updates verified correctly")
+
+    finally:
+        # Cleanup
+        await db_conn.execute("DROP TABLE IF EXISTS test_uuid_multi CASCADE")