#!/usr/bin/python3
import psycopg2
from config import config
# example: create table tbl_game_android_step_log_2021_07 PARTITION OF tbl_game_android_step_log FOR VALUES FROM ('2021-07-01') TO ('2021-08-01');
def create_table(db, table, sub_table, start_date, end_date):
  """ create subtable in the PostgreSQL database"""
  command = "create table {0} PARTITION OF {1} FOR VALUES FROM ('{2[0]}') TO ('{2[1]}');".format(sub_table, table, (start_date, end_date)) 
  conn = None
  try:
    # read the connection parameters
    params = config(section = db)
    # connect to the PostgreSQL server
    conn = psycopg2.connect(**params)
    cur = conn.cursor()
    # create table one by one
    cur.execute(command)
    # close communication with the PostgreSQL database server
    cur.close()
    # commit the changes
    conn.commit()
  except (Exception, psycopg2.DatabaseError) as error:
    print(error)
  finally:
    if conn is not None:
      conn.close()

#!/usr/bin/python3
import datetime
from datetime import date
from dateutil.relativedelta import *
from pg_add_partition_table import create_table
# Get the 1st day of the next month
def get_next_month_first_day(d):
  return date(d.year + (d.month == 12), d.month == 12 or d.month + 1 , 1)
  
def create_sub_table(db, table):
  # Get current date
  d1 = date.today()
  # Get next month's date
  d2 = d1 + relativedelta(months=+1)
  # Get the 1st day of the next month;As the starting value of the partitioned table
  start_date = get_next_month_first_day(d1)
  # Gets the 1st of the next two months as the end value of the partitioned table
  end_date = get_next_month_first_day(d2)
  # get sub table name
  getmonth = datetime.datetime.strftime(d2, '%Y_%m')
  sub_table = table + '_' + getmonth
  create_table(db, table, sub_table, start_date, end_date)
	
if __name__ == '__main__':
  create_sub_table('test', 'tbl_game_android_step_log');

 # 多表操作
  for table in ['tbl_game_android_step_log', 'tbl_game_android_game_log','tbl_game_android_pay_log']:
    create_sub_table('test', table);

adsas=> select * from pg_partition_tree('tbl_game_android_step_log');
        relid        |    parentrelid    | isleaf | level 
-----------------------------------+---------------------------+--------+-------
 tbl_game_android_step_log     |              | f   |   0
 tbl_game_android_step_log_2020_12 | tbl_game_android_step_log | t   |   1
(2 rows)

adsas=> select * from pg_partition_tree('tbl_game_android_step_log');
        relid        |    parentrelid    | isleaf | level 
-----------------------------------+---------------------------+--------+-------
 tbl_game_android_step_log     |              | f   |   0
 tbl_game_android_step_log_2020_12 | tbl_game_android_step_log | t   |   1
 tbl_game_android_step_log_2021_01 | tbl_game_android_step_log | t   |   1
Partition key: RANGE (visit_time)
Partitions: tbl_game_android_step_log_2020_12 FOR VALUES FROM ('2020-12-01 00:00:00') TO ('2021-01-01 00:00:00'),
      tbl_game_android_step_log_2021_01 FOR VALUES FROM ('2021-01-01 00:00:00') TO ('2021-02-01 00:00:00')