Table not created, even after validating the table existence - mysql-connector

Question

class datalog(display_clock):
def con_mysql(self):
cat = mysql.connector.connect(
host="localhost", user="subramanya", passwd="Sureshbabu#4155", database="CFM")
if (cat):
datacursor = cat.cursor()
todaydate = d
check_table = (
"SELECT count(*) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME=%s")
datacursor.execute(check_table, (todaydate,))
result = datacursor.fetchone()
if (result):
self.success_login()
else:
datacursor.execute(
"CREATE TABLE {today}(Sl_no INT NOT NULL AUTO_INCREMENT PRIMARY KEY,date DATE,Start_time TIME,End_time TIME,Item CHAR(255),Weight FLOAT, Amount INTEGER(10))".format(today=todaydate))
self.success_login()
else:
datacursor.Terminate
self.error_display.insert(0.0, "Connecting Database failed!!!")
I tried to check whether any table exists for today's date or not.
if not create the same.
no error occurred. But table not created for sysdate.

Answer 1

Welcome to stackoverflow!
I believe there is a small misconception here. You don't need to check if the table exists beforehand and create it afterward. Most of the current database technologies accept the condition IF NOT EXISTS on CREATE TABLE CLAUSE.
CREATE TABLE IF NOT EXISTS sales (
sale_id INT NOT NULL,
);
It means the table sales will be only created IF NOT EXISTS previously.
Also, I strongly recommend refactoring your code a wee bit. Take as a suggestion (please adapt accordingly your project needs):
from datetime import datetime
class Settings:
# please, avoid hard-coded credentials.
DB_HOST = "localhost"
DB_USER = "subramanya"
DB_PASSWD = "Sureshbabu#4155"
DB_SCHEMA = "CFM"
class datalog(display_clock):
def db_connect(self):
conn = mysql.connector.connect(
host=Settings.DB_HOST,
user=Settings.DB_USER,
passwd=Settings.DB_PASSWD,
database=Settings.DB_SCHEMA
)
if not conn:
raise Exception("Connecting Database failed!!!")
return conn
def ensure_table(self):
conn = self.db_connect()
conn.datacursor.execute("""
CREATE TABLE IF NOT EXISTS `{0}`(
Sl_no INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
date DATE,
Start_time TIME,
End_time TIME,
Item CHAR(255),
Weight FLOAT,
Amount INTEGER(10)
);
""".format(datetime.today().strftime('%Y%m%d')) # format 20200915
)
def run(self):
self.ensure_table()
self.success_login()
There are plenty of ways to write this code, but keep in mind that readability matters a lot.