NotImplementedError: executemany is implemented for simple INSERT statements only - python-3.x

Question

I try to append my vertica (SQL-type) table through pandas using sqlalchemy
import pandas as pd
import sqlalchemy as sa
Create engine to vertica:
def get_engine(base):
engine = sa.create_engine("{sys}+{dri}://{user}:" + \
"{password}#{host}:{port}/{database}".format(**login[base]))
return engine
engine = get_engine('vertica')
Just for clarity a simple query:
table = '***'
sql =\
'''
select *
from public.{table}
'''.format(table=table)
connection = engine.connect()
data = pd.read_sql(sql, connection)
connection.close()
Data is not empty:
print(len(data))
569955
And try to write to the same table:
fields = list(data.columns)
connection = engine.connect()
data.to_sql(table, connection, schema='public', index=False, if_exists='append', chunksize=30000,
dtype={fields[0]:sa.types.Integer,
fields[1]:sa.types.VARCHAR,
fields[2]:sa.types.Integer,
fields[3]:sa.types.Integer,
fields[4]:sa.types.Integer,
fields[5]:sa.types.VARCHAR,
fields[6]:sa.types.VARCHAR,
fields[7]:sa.types.VARCHAR,
fields[8]:sa.types.VARCHAR,
fields[9]:sa.types.VARCHAR,
fields[10]:sa.types.VARCHAR,
fields[11]:sa.types.VARCHAR,
fields[12]:sa.types.DateTime
})
connection.close()
And get this mistake:
...
\Anaconda3\lib\site-packages\sqlalchemy\engine\default.py in do_executemany(self, cursor, statement, parameters, context)
465
466 def do_executemany(self, cursor, statement, parameters, context=None):
--> 467 cursor.executemany(statement, parameters)
468
469 def do_execute(self, cursor, statement, parameters, context=None):
\Anaconda3\lib\site-packages\vertica_python\vertica\cursor.py in executemany(self, operation, seq_of_parameters)
153 else:
154 raise NotImplementedError(
--> 155 "executemany is implemented for simple INSERT statements only")
156
157 def fetchone(self):
NotImplementedError: executemany is implemented for simple INSERT statements only

Answer 1

I got the same error when I was trying to write my data to vertica using sqlalchemy. For my case the issue was the column names. It seems that it can't write column names that include special characters. I could fix the error by removing all the '_', '%' and white space characters from column names in pandas and then I used df.to_sql() to write it in vertica.