Pandas Write table to MySQL: “unable to rollback”

Question

I need help to get this working. I have a pd.DataFrame (df), which I need to load to a MySQL database. I don\'t understand what the error message means and how

Answer 1

I was able to resolve this issue. I was trying to load a large table into MySQL and as a result of which was getting the error. A simple for-loop to upload data in chunks solved the issue ! Many thanks to everyone who replied.

Answer 2

When using sqlalchemy, you should pass the engine and not the raw connection:

engine = create_engine("mysql+mysqldb://...")
df.to_sql('demand_forecast_t', engine, if_exists='replace', index=False)

Writing to MySQL without sqlalchemy (so with specifying flavor='mysql') is deprecated.

When the problem is that you have a too large frame to write at once, you can use the chunksize keyword (see the docstring). Eg:

df.to_sql('demand_forecast_t', engine, if_exists='replace', chunksize=10000)

Answer 3

You can write pandas dataframe in mysql table using mysql flavour(with DBAPI connection) in following ways

step1: install mysqldb module - $ sudo apt-get install python-dev libmysqlclient-dev then $ pip install MySQL-python

step2: make a connection with mysql import MySQLdb con = MySQLdb.connect("hostname","username","password","databasename")

step3: write pandas dataframe in mysql table by using df.to_sql df.to_sql('TableName',con = con,flavor='mysql',if_exists='replace', chunksize=100)

Answer 4

For me this was fixed using

MySQLdb.connect("127.0.0.1","root","","db" )

instead of

MySQLdb.connect("localhost","root","","db" )

and then

df.to_sql('df',sql_cnxn,flavor='mysql',if_exists='replace', chunksize=100)