Issues printing a Dataframe after collecting Data from MySQL - mysql

Question

I hope you can help me with my Issue. I connected python to my database using pyodbc and I think I was able to save the data into a pandas Dataframe, but unfortunatly I cant work with the Dataframe (for example simply print it) aftertwards.
The error Message says "undefined name "DataFrame"".
How do I need to change my Code so I can get the data from MySQL and use the Dataframe afterwards regularly.
Just as a side Information I want to calculate with the dataframe a little using pandas (optional) and then create a plot using Plotnine and add a UI later. just in Case that matters.
#This function I call
def SQLtoPandas(Connection,SQLString,DataFrame):
DataFrame = pd.DataFrame(
pd.read_sql(SQLString,
con=Connection)
)
#If i call this function it works just fine
def SQL_ReadFunction(Connection,SQLString):
cursor=Connection.cursor()
cursor.execute(
SQLString
)
rows = cursor.fetchall()
for row in rows:
print(row)
SQLString = 'select * from employees'
SQL_ReadFunction(Connection,SQLString)
Connection.close
#Doesnt work, moving it inside the connection also doesnt help.
print (DataFrame)

Answer 1

you don't need additional function for this. just use
df=pd.read_sql('select * from employees',con=con)
print(df)
and manipulate df as you wish using pandas.
i would reccomend using jupyter notebook as it displays dataframe nicely.
also note pd.read_sql() already returns pandas DataFrame, no need to reconvert

Answer 2

You have a few things to take care:
Your function can directly have pd.read_sql as it will load your table as a dataframe. You do not need an extra pd.DataFrame.
You have to print your dataframe inside the function, or assign the dataframe outside like df = SQLtoPandas(Connection,SQLString) and have a return df inside your function
Avoid using the keyword DataFrame to name your DataFrame, use df or something else that is not reserved.
Method 1:
Inside your function:
def SQLtoPandas(Connection,SQLString):
df= pd.read_sql(SQLString, con=Connection)
print(df)
Now call your function outside:
SQLtoPandas(Connection, SQLString)
Method 2:
Inside your function:
def SQLtoPandas(Connection,SQLString):
df = pd.read_sql(SQLString, con=Connection)
return df
Now outside your function do:
df = SQLtoPandas(Connection, SQLString)
print(df)