Not able to insert multiple columns in once using executemany

Question

I have two variables to insert in my table.

• user_id - int
• marks - float

and I am having this data for multiple users like this:

user_ids = (-,-,-,-,-,-,-)  **TUPLE**
marks = (-,-,-,-,-,-,-,-)    **TUPLE**

I want to insert this data into my table using executemany and I am executing this query in my flask snippet:

con = pymysql.connect(
    host=host,
    user=user,
    password=password,
    db=db,
    charset=charset,
    cursorclass=pymysql.cursors.DictCursor,
    port=port,
)
cur = con.cursor()
percs = calcattnonull()

# percs contains list of dictionaries.
# {[<'user_id'>: <'marks'>], [<'user_id'>: <'marks'>]........}
id_ = []
perc_ = []
final = []
for perc in tqdm(percs):
    id_.append(perc["user_id"])
    perc_.append(perc["att_perc"])

id_ = tuple(id_)
perc_ = tuple(perc_)
final.append(id_)
final.append(perc_)
cur.executemany(
    "UPDATE dream_offline_calculate SET (user_id,att_percentage) VALUES (?,?)",
    final,
)
con.commit()

I am getting this error again and again: TypeError: not all arguments converted during string formatting

Thanks in advance for helping me.

Answer 1

executemany takes an iterable of the same placeholders you would use when calling execute several times.

So if your original query would be

cur.execute(
  "UPDATE dream_offline_calculate SET (user_id,att_percentage) VALUES (?,?)",
  (user_id, att_perc),
)

the equivalent executemany would be

cur.executemany(
  "UPDATE dream_offline_calculate SET (user_id,att_percentage) VALUES (?,?)",
  [(user_id, att_perc)],
)

So that said, simply

cur.executemany(
    "UPDATE dream_offline_calculate SET (user_id,att_percentage) VALUES (?,?)",
    [(perc["user_id"], perc["att_perc"]) for perc in percs],
)

should do the trick.