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pythoncassandracassandra-driver

Problem with python driver in Cassandra when use prepared statements

when I want to update a set item in Cassandra table with python code like following

ps = session.prepare( """ UPDATE test,tbl SET val = val + {'?'} where name = ? and id = ?;""" )
bs = bind(ps, ['name', 'name', 1])
session.execute(bs)

I got error

Too many arguments provided to bind() (got 3, expected 2)

the problem is {'?'} that cant identified by prepared. I test {\'?\'} but nothing change.

Solution

  • Update: forgot about that syntax...

    You need to use following syntax:

    UPDATE test,tbl SET val = val + ? where name = ? and id = ?;

    and bind with set as first parameter:

    bs = bind(ps, [set(['name']), 'name', 1])

    Original answer:

    You don't need to put quotes around ? character - when bind happens, it's correctly quotes the text & other types.

    P.S. Please note, that if you use {?}, this means that you always insert one element into the set. If you need more, then you need to use just ?, and pass a python set as an argument.