On 20/01/20 4:35 AM, Python wrote:
^Bart wrote:
I ran this code:
#!/usr/bin/python
import MySQLdb
# Open database connection
db = MySQLdb.connect("localhost","root","MyPwd","MyDB")
# prepare a cursor object using cursor() method
cursor = db.cursor()
# Drop table if it already exist using execute() method.
cursor.execute("DROP TABLE IF EXISTS EMPLOYEE")
# Create table as per requirement
sql = """CREATE TABLE EMPLOYEE (
FIRST_NAME CHAR(20) NOT NULL,
LAST_NAME CHAR(20),
AGE INT,
SEX CHAR(1),
INCOME FLOAT )"""
cursor.execute(sql)
# disconnect from server
db.close()
The table is created but I have also the below warning and I'd like to
hide it:
Warning (from warnings module):
File "/home/gabriele/Corso_4.0/Python/MySQL_create_table.py", line 11
cursor.execute("DROP TABLE IF EXISTS EMPLOYEE")
Warning: (1051, "Unknown table 'gabfood.EMPLOYEE'")
>>>
import warnings
with warnings.catch_warnings():
warnings.simplefilter("ignore")
# your code
Recommend starting at the source (hah!) of the problem: MySQL!
(above includes (small!) risk of Python warnings becoming wrapped-up in
what is actually a MySQL-specific 'problem')
NB I use the MySQL Connector/Python, downloaded from the MySQL Dev site
(also source of useful manuals).
- intriguingly I've always understood the manuals to say that raising
Warnings is False, ie suppressed; yet history shows that the behavior
is/has always been (to my recollection) that Warnings are raised...
- similarly, we both seem to expect that if the SQL includes "IF EXISTS"
we've already foreseen and wish to side-step the problem???
Option 1:
Amongst the connector's batteries-included are a bunch of Exception
classes including "mysql.connector.errors.Warning". These enable queries
to be wrapped in try-except blocks, eg:
try:
cursor.execute(sql)
except MySQL_warning:
# which could be more precise, as you desire
# ie check tbl != exist, then pass
Option 2:
Please review the MySQL Connectors and APIs guide (or the Python-only
version). You will find Section 7.5 "Connector/Python Coding Examples"
illustrative. (there are also some (rather thin) tutorials - but better
than nothing!). Section 7.9 "Connector/Python API Reference" offers
additional MySQL 'commands' which you might use to suppress the Warning
before it is raised.
--
Regards =dn
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