"AttributeError: 'NoneType' object has no attribute 'fetchall'" loading data to Elastisearch

Question

I want to load data from PostgreSQL to Elasticsearch and I write below code, but it gives me the error in for loop, my code is as below:

from elasticsearch import Elasticsearch

#res = requests.get('http://localhost:9200')
es = Elasticsearch([{'host': 'localhost', 'port': 9200}])
sql_conn = psycopg2.connect(host="localhost",database="priyanka",user="postgres",password="admin")
sql_cursor = sql_conn.cursor()
sql=('SELECT * FROM "Sales"')
sql_cursor=sql_cursor.execute(sql)
tempList=[]
tmp = {}
for row in sql_cursor.fetchall():
    print("1")
    Sales_id =str(row[0])
    Product_name =str(row[1])
    sales =str(row[2])

    tmp["Sales_id"]=Sales_id
    tmp["name"]=Product_name
    tmp["sales"]=sales

Error is:

Traceback (most recent call last):
  File "D:/Priyanka Pagar/Softwares/Team/Python37/elastic - Copy.py", line 16, in <module>
    for row in sql_cursor.fetchall():
AttributeError: 'NoneType' object has no attribute 'fetchall'

Answer 1

Change

sql_cursor=sql_cursor.execute(sql)

to

sql_cursor.execute(sql)

Because the execute method returns none, this re-assignment destroys the ability to later fetch the results from the cursor.