From 55b6fca9c9bc989b7f15e900e8b66b6047e3afd8 Mon Sep 17 00:00:00 2001
From: Milan Bariya <52292922+MilanBariya@users.noreply.github.com>
Date: Fri, 13 May 2022 16:11:43 +0530
Subject: [PATCH] Fix #4924: Clickhouse view lineage (#4929)

* Fix: Clickhouse view lineage

* Fix: Clickhouse view lineage

* Fix: Clickhouse view lineage
---
 .../metadata/ingestion/source/clickhouse.py   | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/ingestion/src/metadata/ingestion/source/clickhouse.py b/ingestion/src/metadata/ingestion/source/clickhouse.py
index 21fd1a24d45..f818864f3e4 100644
--- a/ingestion/src/metadata/ingestion/source/clickhouse.py
+++ b/ingestion/src/metadata/ingestion/source/clickhouse.py
@@ -19,6 +19,9 @@ from sqlalchemy import util as sa_util
 from sqlalchemy.engine import reflection
 from sqlalchemy.util import warn
 
+from metadata.generated.schema.entity.services.connections.database.clickhouseConnection import (
+    ClickhouseConnection,
+)
 from metadata.generated.schema.entity.services.connections.metadata.openMetadataConnection import (
     OpenMetadataConnection,
 )
@@ -136,15 +139,23 @@ def get_table_comment(self, connection, table_name, schema=None, **kw):
     return {"text": None}
 
 
+@reflection.cache
+def get_view_definition(self, connection, view_name, schema=None, **kw):
+    try:
+        query = f"select create_table_query from system.tables where engine = 'View' and name='{view_name}' and database='{schema}'"
+        result = connection.execute(query)
+        view_definition = result.fetchone()
+        return view_definition[0] if view_definition else ""
+    except Exception:
+        return ""
+
+
 ClickHouseDialect.get_unique_constraints = get_unique_constraints
 ClickHouseDialect.get_pk_constraint = get_pk_constraint
 ClickHouseDialect._get_column_type = _get_column_type
 ClickHouseDialect.get_table_comment = get_table_comment
 RequestsTransport.execute = execute
-
-from metadata.generated.schema.entity.services.connections.database.clickhouseConnection import (
-    ClickhouseConnection,
-)
+ClickHouseDialect.get_view_definition = get_view_definition
 
 
 class ClickhouseSource(SQLSource):