(Pymongo) connect/adding relationship with two column from different collections in MongoDB-CodePudding

I'm practicing use python to commit rollback MongoDB (Pymongo)

For example, I have two collections, one collection store all amount of money of each user and log collection is saving data of with roll or input money in bank

total_money_collection {"user": "Joy" , "total_money" : 100, "ID" : 999}
log_money_collection {"user": "Joy" , "in_out_put_money" : null , "ID" : 999}

I need a hand for simpler way, maybe there is a short pymongo command,or MongoDB can do such operation that just extract the result is fine etc.

If I input from log_money_collection {"user": "Joy" , "in_out_put_money" : -7 , "ID" : 999},
how can "in_out_put_money" column effect "total_money" column

Expected output:

total_money_collection {"user": "Joy" , "total_money" : 93, "ID" : 999}

This is my code (I made lot of make an unnecessary move, I believe there is a simpler way):

import pymongo
import datetime
import json
from bson.objectid import ObjectId
from bson import json_util
import re

def init_db(ip, db, coll):
    myclient = pymongo.MongoClient('mongodb://'   ip   '/')
    mydb = myclient[db]
    mycol = mydb[coll]

    return mydb, mycol, myclient
       

def Quy_data(  mycol , find_values_json , one_or_many_bool):
    try:   
            if one_or_many_bool:
                x = []
                
                for y in  mycol.find(find_values_json):
                    x.append(y)
                
                cash_all_value = mycol.find({},{ "Cash_$": 1 })

            else:
                x = mycol.find_one(find_values_json)
                cash_all_value = mycol.find({},{ "Cash_$": 1 })
            return x , cash_all_value
    except Exception as e:
            msg_fail_reason = "error in ins_data function"
            return msg_fail_reason


ip_input = input("Enter the ip: ")
exist_DB_name = input("Enter exist DB name: ")



def parse_json(data):
    return json.loads(json_util.dumps(data))



try:
    exist_coll = input("Enter exist collection (ex: 10_20_cash_all , 10_20_cash_log ): ")
    mydb, mycol , myclient = init_db(ip_input, exist_DB_name, exist_coll)
    
    with myclient.start_session(causal_consistency=True) as session:

        #  Open a transaction session 
        with session.start_transaction():

            # mycol.insert_one({'Name': ' Gosum '}, session=session)

            if exist_coll == "10_20_cash_all":
                    # I set find all ( = find )
                    one_or_many_bool = True
                    findvalues_str = input("Enter find data conditions: ")

                    find_values_json =json.loads(findvalues_str)
                    x , cash_all_value = Quy_data( mycol , find_values_json , one_or_many_bool )

                             # if someone want data in json 
                    modified_data_x_json = parse_json(x)
                    cash_all_value_json = parse_json(cash_all_value)
                    a = str(cash_all_value_json)


                    print(modified_data_x_json)
                    print(type(modified_data_x_json))

                    print("= = = = = ")
                    print(a)
                    print(type(a))
                    b = re.search("'Cash_$':  (.*)", a)
                    print(b)

            
except Exception as e:
    #  Output exception content 
    print(e)

output for my (I find the user Joy, and try to extract the number after "total_money" then subtract "in_out_put_money")

Enter the ip: localhost
Enter exist DB name: (practice_10_14)-0004444
Enter exist collection (ex: 10_20_cash_all , 10_20_cash_log ): 10_20_cash_all
Enter find data conditions: { "name": "Joy" }
[{'_id': {'$oid': '6348d73be94317989175dc2d'}, 'name': 'Joy', 'ID': 999, 'Age': 23, 'time': {'$date': '2022-10-17T09:11:54Z'}, 'total_money': 100}]
<class 'list'>
= = = = =
[{'_id': {'$oid': '6348d73be94317989175dc2d'}, 'total_money': 100}, {'_id': {'$oid': '6348d73be94317989175dc2e'}, 'total_money': 100}, {'_id': {'$oid': '6348d73be94317989175dc2f'}, 'total_money': 100}, {'_id': {'$oid': '6348d73be94317989175dc30'}, 'total_money': 100}, {'_id': {'$oid': '6348d73be94317989175dc31'}, 'total_money': 100}, {'_id': {'$oid': '635112dea1fa85dd0cfe590b'}, 'total_money': 100}]
<class 'str'>
None

A simple step of commit rollback MongoDB with account money I turn a huge circle to get it, I need a hand for simpler way, maybe there is a short pymongo command,or MongoDB can do so that just extract the result is fine etc

CodePudding user response：

the same concept make ur {"user": "Joy" , "total_money" : 93, "ID" : 999},
the "total_money" become lesser by subtracting them, for sure U can't directly do that, like python (4 - 1 something)....

here is the code:

import pymongo
import datetime
import json
from bson.objectid import ObjectId
from bson import json_util
import re

myclient = pymongo.MongoClient("mongodb://localhost/")
mydb = myclient["(practice_10_14)-0004444"]



# UD_db_data means update
def UD_db_data(mycol , myquery_json, newvalues_json, one_or_many_bool):

    if one_or_many_bool == True:
        x = mycol.update_many(myquery_json, newvalues_json)
    else:
        x = mycol.update_one(myquery_json, newvalues_json)
    return x


# Quy_data = query find db_data
def Quy_data( mycol ,find_values_json , one_or_many_bool):
    try:   
            if one_or_many_bool:
                x = []
                
                for y in  mycol.find(find_values_json):
                    x.append(y)
                
            else:
                x = mycol.find_one(find_values_json)
            return x 
    except Exception as e:
            msg_fail_reason = "error in ins_data function"
            return msg_fail_reason


mycol_one = mydb["10_20_cash_all"]
mycol_two = mydb["10_20_cash_log"]
mycol_3rd = mydb["10_20_cash_info"]

 # already store 100$ in bank
# doc_two = {"ID" :  100998 , "Cash_log$" : 5 }      # withdraw 5$ from bank

doc_two = input("Enter ID and log amount$: ")
doc_3rd = input("Enter extra info: ")

doc_two_dic = json.loads(doc_two)
doc_3rd_dic = json.loads(doc_3rd)

# doc_3rd = {"note" :  "today is good" }

ID_input = doc_two_dic['ID']
print("ur id is :"   str(ID_input))
doc_one = {"ID" :  ID_input}

with myclient.start_session() as s:
    cash_all_result = mycol_one.find_one(doc_one, session=s)

    def cb(s):
            try:
                    while True:
                            cash_all_result = mycol_one.find_one(doc_one, session=s)
                            mycol_two.insert_one(doc_two_dic, session=s)

                            # print( 3/0 )

                            mycol_3rd.insert_one(doc_3rd_dic, session=s)

                            
                    

                            print( "now total is :"   str(cash_all_result['Cash_$']) )
                            Cash_total_int = int(cash_all_result['Cash_$'])
                            log_int = int(doc_two_dic['Cash_log$'])

                            if Cash_total_int < log_int:
                                print("error: withdraw is over ur balance")
                                break

                            new_Cash_total = Cash_total_int - log_int
                            print("now total is :"   str(new_Cash_total))

                            newvalues_json = { "$set" : {"Cash_$" : new_Cash_total } }
                            
                            mycol_one.update_one(doc_one , newvalues_json, session=s)


                            fail_condition_json = {"ok" : 1 , "fail reason" : "no error "}
                            print(fail_condition_json)
                            return fail_condition_json

            except Exception as e:
                    fail_condition_json = {"ok" : 0 , "fail reason" : "error raise on start_session()"}
                    print(fail_condition_json)
                    return fail_condition_json
            
    s.with_transaction(cb)

I believe I do the calculation with 3 collection's data
and the output is below

Enter ID and log amount$: {"ID" :  100998 , "Cash_log$" : 23 }
Enter extra info: {"note" :  "today is no good" }
ur id is :100998
now total is :72
now total is :49
{'ok': 1, 'fail reason': 'no error '}