bigquery-frame_flatten_example.py

bq = BigQueryBuilder(get_bq_client())
df = bq.sql('''SELECT 1 as id, STRUCT(1 as a, STRUCT(1 as c, 1 as d) as b) as s''')
df.printSchema()
# root
#  |-- id: INTEGER (NULLABLE)
#  |-- s: RECORD (NULLABLE)
#  |    |-- a: INTEGER (NULLABLE)
#  |    |-- b: RECORD (NULLABLE)
#  |    |    |-- c: INTEGER (NULLABLE)
#  |    |    |-- d: INTEGER (NULLABLE)

flatten(df).printSchema()
# root
#  |-- id: INTEGER (NULLABLE)
#  |-- s_a: INTEGER (NULLABLE)
#  |-- s_b_c: INTEGER (NULLABLE)
#  |-- s_b_d: INTEGER (NULLABLE)