Update for null values in array

backend/field_update

@@ -192,7 +192,10 @@ class Raw:
             t2 AS (
                 SELECT 
                     t1.osm_id,
-                    COALESCE(array_agg(cg.{source_column}),ARRAY[0]::integer[]) AS aa_fids
+                    CASE 
+                        WHEN COUNT(cg.{source_column}) = 0 THEN ARRAY[0]::integer[]
+                        ELSE array_agg(COALESCE(cg.id, 0))
+                    END AS aa_fids
                 FROM 
                     t1
                 LEFT JOIN 

backend/replication

@@ -532,7 +532,12 @@ def update_country(conn, timestamp, table_name, c_id=None, boundary=None):
     """Updates country column in table , It intersects it's newly inserted data's geometry to the boundaries loaded to underpass and populates info , in order to use multicolumn indexes with geometry"""
     # array value 1000 means rest of the world
     with conn.cursor() as cur:
-        update_query = f"""WITH t1 AS (SELECT osm_id, ST_Centroid(geom) AS geom FROM {table_name} WHERE "timestamp" >= '{timestamp}'), t2 AS (SELECT t1.osm_id, COALESCE(array_agg(cg.id),ARRAY[0]::integer[]) AS aa_fids FROM t1 LEFT JOIN countries cg ON ST_Intersects(t1.geom, cg.geometry) GROUP BY t1.osm_id) UPDATE {table_name} uw SET country = t2.aa_fids FROM t2 WHERE t2.osm_id = uw.osm_id;"""
+        update_query = f"""WITH t1 AS (SELECT osm_id, ST_Centroid(geom) AS geom FROM {table_name} WHERE "timestamp" >= '{timestamp}'), t2 AS (SELECT t1.osm_id,     
+        CASE 
+            WHEN COUNT(cg.id) = 0 THEN ARRAY[0]::integer[]
+            ELSE array_agg(COALESCE(cg.id, 0))
+        END AS aa_fids 
+        FROM t1 LEFT JOIN countries cg ON ST_Intersects(t1.geom, cg.geometry) GROUP BY t1.osm_id) UPDATE {table_name} uw SET country = t2.aa_fids FROM t2 WHERE t2.osm_id = uw.osm_id;"""
 
         cur.execute(update_query)
     conn.commit()