WIP

src/sqlfluff/dialects/dialect_sqlite.py

@@ -490,6 +490,20 @@ class PragmaStatementSegment(BaseSegment):
     )
 
 
+class OverClauseSegment(ansi.OverClauseSegment):
+    """An OVER clause for window functions."""
+
+    match_grammar: Matchable = Sequence(
+        "OVER",
+        OneOf(
+            Ref("SingleIdentifierGrammar"),  # Window name
+            Bracketed(
+                Ref("WindowSpecificationSegment", optional=True),
+            ),
+        ),
+    )
+
+
 class StatementSegment(ansi.StatementSegment):
     """Overriding StatementSegment to allow for additional segment parsing."""
 

test/fixtures/dialects/sqlite/select.sql

@@ -1 +1,25 @@
 SELECT a FROM foo LIMIT 10;
+
+WITH time_cte AS (
+  SELECT
+      branch,
+      created_at,
+      time,
+      cast(time - LAG (time, 1, time) OVER (ORDER BY time) as real) AS time_spent
+  FROM heartbeats h
+  WHERE user_id = ? AND created_at >= DATE('now', 'start of day')
+  ORDER BY id
+  LIMIT -1 OFFSET 1
+)
+SELECT
+    branch as name,
+    cast(time_spent as real) as time_spent,
+    cast(time_spent / (SELECT SUM(time_spent) FROM time_cte) as real) as time_percentage
+FROM (
+    SELECT
+        branch,
+        cast(SUM(time_spent) as real) AS time_spent
+    FROM time_cte
+    GROUP BY branch
+    ORDER BY time_spent DESC
+);