def retrieve_related_attribute(conn, database_srid, region, region_srid,
datasource, entitytype, attribute_name, limit):
with closing(conn.cursor()) as cursor:
attributestore = AttributeStore.get_by_attributes(cursor, datasource, entitytype)
full_base_tbl_name = attributestore.history_table.render()
relation_name = get_relation_name(conn, "Cell", entitytype.name)
relation_cell_site_name = get_relation_name(conn, "Cell", "Site")
bbox2d = transform_srid(set_srid(make_box_2d(region), region_srid),
database_srid)
query ="""
SELECT public.first(entity_id) AS entity_id, public.first(related_id) AS related_id,
min(timestamp) AS "timestamp", \"{0}\" FROM (
SELECT entity_id, related_id, timestamp, \"{0}\", sum(change) OVER w2 AS run
FROM ( SELECT entity_id, related_id, timestamp, \"{0}\",
CASE WHEN \"{0}\" <> lag(\"{0}\" ) OVER w THEN 1 ELSE 0 END AS change
FROM ( SELECT r.source_id as entity_id, r.target_id as related_id,
base_table.timestamp, base_table.\"{0}\" FROM {1} base_table
JOIN relation.\"{2}\" r ON r.target_id = base_table.entity_id
JOIN relation.\"{3}\" site_rel on site_rel.source_id = r.source_id
JOIN gis.site site ON site.entity_id = site_rel.target_id AND
site.position && {4} ) a WINDOW w AS (PARTITION BY entity_id ORDER BY
timestamp asc)) t WINDOW w2 AS (PARTITION BY entity_id ORDER BY
timestamp ASC)) runs GROUP BY entity_id, \"{0}\" , run""".format(
attribute_name, full_base_tbl_name, relation_name,
relation_cell_site_name, bbox2d)
with closing(conn.cursor()) as cursor:
try:
cursor.execute(query, region)
except psycopg2.ProgrammingError:
conn.rollback()
rows = []
else:
rows = cursor.fetchall()
result = {}
for entity_id, related_id, timestamp, value in rows:
if not value is None:
if entity_id not in result:
result[entity_id] = {}
if related_id not in result[entity_id]:
result[entity_id][related_id] = []
result[entity_id][related_id].append(
(timestamp, value))
return result
