Develop Reference

How do I convert a JSON file to a SQL lite database if the JSON file has multiple values?

I'm new to using Python sqlite and parsing json files. I'm trying to create a (3 table) database using python sqlite. I am able to create these tables using the code below, but now I need to populate the tables using a json file. How do I add the json file to the tables when there are multiple values (as seen below)? For example, there are multiple items and I want to create a counter variable (itemid) for each item in the order.
import sqlite3
from sqlite3 import Error
def create_connection(db_file):
""" create a database connection to the SQLite database
specified by db_file
:param db_file: database file
:return: Connection object or None
"""
conn = None
try:
conn = sqlite3.connect(db_file)
return conn
except Error as e:
print(e)
return conn
def create_table(conn, create_table_sql):
""" create a table from the create_table_sql statement
:param conn: Connection object
:param create_table_sql: a CREATE TABLE statement
:return:
"""
try:
c = conn.cursor()
c.execute(create_table_sql)
except Error as e:
print(e)
def main():
database = r"C:\sqlite\db\pythonsqlite.db"
sql_create_items_table = """ CREATE TABLE IF NOT EXISTS items (
orderid integer PRIMARY KEY,
itemid integer PRIMARY KEY,
name text,
price numeric); """
sql_create_charges_table = """CREATE TABLE IF NOT EXISTS charges (
FOREIGN KEY (items_orderid) REFERENCES items (orderid),
date datetime,
subtotal numeric,
taxes numeric,
total numeric);"""
sql_create_payment_table = """CREATE TABLE IF NOT EXISTS payment (
FOREIGN KEY (items_orderid) REFERENCES items (orderid),
card_type text,
card_number integer,
zip text,
cardholder text,
method text);"""
# create a database connection
conn = create_connection(database)
# create tables
if conn is not None:
# create items table
create_table(conn, sql_create_items_table)
# create charges table
create_table(conn, sql_create_charges_table)
# create payment table
create_table(conn, sql_create_payment_table)
else:
print("Error! cannot create the database connection.")
if __name__ == '__main__':
main()
This is an example of the json file entries:
{
"orders": [
{
"items": [
{
"name": "coffee",
"price": 2.75
},
{
"name": "espresso",
"price": 1.25
}
],
"charges": {
"date": "04/01/21 11:10",
"subtotal": 4.0,
"taxes": 0.28,
"total": 4.28
},
"payment": {
"card_type": "visa",
"last_4_card_number": "6072",
"zip": "21213",
"cardholder": "Andrew Luna",
"method": "credit_card"
}
}
}

How to insert JSON file data in to table

I have a sample json file named a.json
The json data in a.json is as:
{
"a cappella": {
"word": "a cappella",
"wordset_id": "5feb6f679a",
"meanings": [
{
"id": "492099d426",
"def": "without musical accompaniment",
"example": "they performed a cappella",
"speech_part": "adverb"
},
{
"id": "0bf8d49e2e",
"def": "sung without instrumental accompaniment",
"example": "they sang an a cappella Mass",
"speech_part": "adjective"
}
]
},
"A.D.": {
"word": "A.D.",
"wordset_id": "b7e9d406a0",
"meanings": [
{
"id": "a7482f3e30",
"def": "in the Christian era",
"speech_part": "adverb",
"synonyms": [
"AD"
]
}
]
},.........
}
As suggested in my previous question I am looking on how to insert this data in to tables
Word: [word, wordset_id]
Meaning: [word, meaning_id, def, example, speech_part
Synonym: [word, synonym_word]
I tried reading file as:
import json
with open('a.json') as f:
d = json.load(f)
when I tried printing all words as:
for word in d:
print(word)
I got all words, but failed to get wordset_id for the same.
How can I insert the word and wordset_id in to the table word for the json format as above?
DBconnection as:
from flask import Flask
from flaskext.mysql import MySQL
app = Flask(__name__)
mysql = MySQL()
app.config['MYSQL_DATABASE_USER'] = 'root'
app.config['MYSQL_DATABASE_PASSWORD'] = 'root'
app.config['MYSQL_DATABASE_DB'] = 'wordstoday'
app.config['MYSQL_DATABASE_HOST'] = 'localhost'
mysql.init_app(app)
conn = mysql.connect()
cursor =conn.cursor()

When you try to execute code:
for word in d:
print(word)
It will only print the keys of the json object, not complete value. Instead, you can try doing something like this,
for word in d:
word_obj = d[word]
wordset_id = word_obj['wordset_id']
sql = "INSERT INTO Word (word, wordset_id) VALUES (%s, %s)"
values = (word, wordset_id)
cursor.execute(sql, values)
meaning_obj_list = d[word]['meanings']
for meaning_obj in meaning_obj_list:
meaning_id = meaning_obj['id']
definition = meaning_obj['def']
example = meaning_obj.get('example', None) # since it is not guaranteed that "example" key will be present in the data, it is safer to extract the value this way
speech_part = meaning_obj['speech_part']
sql = "INSERT INTO Meaning (word, meaning_id, def, example, speech_part) VALUES (%s, %s, %s, %s, %s)"
values = (word, meaning_id, definition, example, speech_part)
cursor.execute(sql, values)
db.commit()
Also, refrain from using the keys names such as def as this is a keyword in python.

Store and use json in MSSQL with python

I'm trying to upload a test JSON string to SQL Server
json_string = """ {
"orderID": 42,
"customerName": "John Smith",
"customerPhoneN": "555-1234",
"orderContents": [
{
"productID": 23,
"productName": "keyboard",
"quantity": 1
},
{
"productID": 13,
"productName": "mouse",
"quantity": 1
}
],
"orderCompleted": true
} """
parsed_string = json.loads(json_string)
cursor.execute("update Table set Status = ? where Name like ? ",(json.dumps(parsed_string), "Blabla"))
cnxn.commit()
How to return and work with this JSON from the database?
cursor.execute("""select Status from Table where Name like ?""", "Blabla")
rows = cursor.fetchall()
How can I print the value of the JSON?

Use the JSON data type that is supported in MySQL. You can find more about it here:
https://dev.mysql.com/doc/refman/5.7/en/json.html

s = json.dumps(DATA)
cursor.execute("update Table set Status = ? where Name like ? ",(s, "Blabla"))
cnxn.commit()
and
cursor.execute("""select Status from Table where Name like ?""", "Blabla")
res = cursor.fetchall()
DATA = json.loads(res[0][X])

inserting JSON object into MySQL using Python

I'm new to python and trying to work out how to insert some JSON into MySQL table.
How can I insert my JSON Object into MySQL using Python?
Here is the code that I am using
import requests
import urllib.request
import json
import pymysql
con = pymysql.connect(host = 'localhost',user = 'root',passwd = 'root',db = 'micro')
cursor = con.cursor()
url = 'https://api.amazon.com/v1/products(onlineAvailability=true)?pageSize=100&show=upc,sku,salePrice&page=45&callback=JSON_CALLBACK&format=json'
urllib.request.urlopen(url).read()
response = urllib.request.urlopen(url).read()
json_obj = str(response, 'utf-8')
cursor.execute("INSERT INTO bestb (sku, upc, salePrice) VALUES (%s,%s,%s)", (sku, upc, salePrice))
con.commit()
con.close()
print (json_obj)
here is the JSON that i'm trying to parse.
"products": [
{
"upc": "715187763623",
"sku": 1833591,
"salePrice": 13.99
},
{
"upc": "8809269504036",
"sku": 26220187,
"salePrice": 16.99
}
]
})
Thanks in advance.

Use json.loads(string) to convert json string to Python object. And then you can use it as normal dictionary and list
BTW: you have incorrect JSON in your example
response = b'''{"products": [
{
"upc": "715187763623",
"sku": 1833591,
"salePrice": 13.99
},
{
"upc": "8809269504036",
"sku": 26220187,
"salePrice": 16.99
}
]
}'''
json_obj = json.loads(response.decode('utf-8'))
#print(json_obj["products"][0]["upc"])
for product in json_obj["products"]:
print("upc:", product["upc"])
print("sku:", product["sku"])
print("salePrice:", product["salePrice"])
print('---')
cursor.execute("INSERT INTO bestb (sku, upc, salePrice) VALUES (%s,%s,%s)", (product["sku"], product["upc"], product["salePrice"]))

Query a multi-level JSON object stored in MySQL

I have a JSON column in a MySQL table that contains a multi-level JSON object. I can access the values at the first level using the function JSON_EXTRACT but I can't find how to go over the first level.
Here's my MySQL table:
CREATE TABLE ref_data_table (
`id` INTEGER(11) AUTO_INCREMENT NOT NULL,
`symbol` VARCHAR(12) NOT NULL,
`metadata` JSON NOT NULL,
PRIMARY KEY (`id`)
);
Here's my Python script:
import json
import mysql.connector
con = mysql.connector.connect(**config)
cur = con.cursor()
symbol = 'VXX'
metadata = {
'tick_size': 0.01,
'data_sources': {
'provider1': 'p1',
'provider2': 'p2',
'provider3': 'p3'
},
'currency': 'USD'
}
sql = \
"""
INSERT INTO ref_data_table (symbol, metadata)
VALUES ('%s', %s);
"""
cur.execute(sql, (symbol, json.dumps(metadata)))
con.commit()
The data is properly inserted into the MySQL table and the following statement in MySQL works:
SELECT symbol, JSON_EXTRACT(metadata, '$.data_sources')
FROM ref_data_table
WHERE symbol = 'VXX';
How can I request the value of 'provider3' in 'data_sources'?
Many thanks!

Try this:
'$.data_sources.provider3'
SELECT symbol, JSON_EXTRACT(metadata, '$.data_sources.provider3)
FROM ref_data_table
WHERE symbol = 'VXX';

the JSON_EXTRACT method in MySql supports that, the '$' references the JSON root, whereas periods reference levels of nesting. in this JSON example
{
"key": {
"value": "nested_value"
}
}
you could use JSON_EXTRACT(json_field, '$.key.value') to get "nested_value"