In this blog post, we will be discussing how to merge a normalized data structure to a Key-Value pair with a JSON.
Let's pick a scenario with customer and their Orders
Table 1 – Customer and Order Relationship
The relationship between customer and order is 1..n. The order list below belongs to two different customers. The dataset in Table 2 is transformed and stored in the DB (either relational or NoSQL dbs) as mentioned in Table 3
Table 2 – Orders
Table 3 – Customer and Orders in key-value pair (JSON)
As customers place new orders, the dataset in Table 4 must be merged with the already existing JSON set to produce a table set as mentioned in Table 5.
Table 4 – New orders from Customer
Table 5 – Merged orders
dfneworders = pd.read_csv('C:\Temp\Outputfile\Blog\Orders.txt')
dfpreviousordercopy = pd.read_csv('C:\Temp\Outputfile\Blog\Output_Json.txt',quotechar="'", sep = "|")
rows = 
_ = dfpreviousordercopy.apply(lambda rowval: rows.append(pd.read_json(rowval['JSON'], orient='records')), axis=1)
dfintegratedorders = pd.concat([pd.concat(rows[0:]), dfneworders])
dftransposed = pd.DataFrame(dfintegratedorders.groupby(['CustCode']).apply(lambda dfsub: dfsub.to_json(orient='records'))).reset_index()
dftransposed.columns = ['CustCode','JSON']
dftransposed.to_csv('C:\Temp\Outputfile\Blog\Output_MergedFile_withJson.txt', index=False, quotechar="'", sep = "|")
The python script extracts from old JSON dataset and integrates new orders and rebuild the JSON.