Not getting any rows

Python
1

So, I am playing with Python and mysql.

I built a database with 2 tables in it. I have a csv file with information to put in the tickers table. Now I have some information and need to continually update this table. However, I don’t want to put in data if that data is already there (the data I put in does not change over time).

However, when I try to find known data in the tickers table, the rows back from the fetchone() is “None”. I know I am asking for the correct information since I tried the Select statement from MySQL workbench and get stuff back.

Any help is greatly appreciated since I am just starting to use Python and MySQL.

Here is my code:

import pandas as pd
import mysql.connector
import DBcm

mydb = mysql.connector.connect(
    host= '',
    user= "",
    password= "",
    database= ""
)

mycursor = mydb.cursor()

inputFileName = "tickersfile.csv"
df = pd.read_csv(inputFileName)
df.head()

ticker_list = df.values.tolist() #change dataframe to list

for ticker in ticker_list:
    
    #first, search for the ticker to verify that this is a new item.
    
    _SQL = """select ticker from tickers where ticker = '%s'"""
    sql_search = "select ticker from ticker where ticker = '" + ticker[0] + "'"
    
    mycursor.execute(_SQL, sql_search)
    row = mycursor.fetchone()
    mydb.commit()

    if row > 0:
        print("Found ticker " + ticker)
    else:
        print("Ticker " + ticker + "not in database")
2

You’re calling mycursor.execute wrong. The second argument is the list of parameters for the query. You also need to leave the quotes off around %s – dbapi will add them automatically.

Here’s some documentation for cursor.execute. It’s for sqlite, but the API is the same for mysql.