MySqlDb throws Operand should contain 1 column(s) on insert ignore statement

Andy picture Andy · Mar 3, 2014 · Viewed 7.1k times · Source

While looking at some of the websocket methods that stack exchange offers, I wanted to save a few data points into a MySQL database. However, when I attempt to run an executemany command, I get the following error:

_mysql_exceptions.OperationalError: (1241, 'Operand should contain 1 column(s)')

While looking around SO, I found many examples of this error, but they have dealt with removing parenthesis on SELECT statements. I'm not using a SELECT. I'm attempting to INSERT.

A short, contained, example of my code looks like this:

import MySQLdb as mdb
db = mdb.connect(host='localhost',user='myuser',db='qs',passwd='mypass',use_unicode=True,charset='utf8')
cur = db.cursor()
db_qry = """INSERT IGNORE INTO questions (id, site_base, title, body_sum, tags, last_act_dt, url, owner_url, owner, api_site) values (%s,%s,%s,%s,%s,%s,%s,%s,%s,%s)"""


parms = [(u'mathematica.stackexchange.com', 
43248, 
u'How to plot “Normalized distance” in this problem', 
u"Problem: there are two particles whose equationsof motion both satisfy -n Abs[x[t]]^n/x[t] == x''[t]. But their initial conditions are different: one is x'[0] == 0, x[0] == 2;another is x'[0] == 0, ...", 
[u'plotting', u'equation-solving', u'differential-equations', u'numerical-integration', u'notebooks'],
1393801095,
u'http://mathematica.stackexchange.com/questions/43248/how-to-plot-normalized-distance-in-this-problem',
u'http://mathematica.stackexchange.com/users/12706/lawerance', u'Lawerance', u'mathematica')]

cur.executemany(db_qry, parms)
cur.commit()

Am I using the executemany incorrect? Or missing another aspect of the parms list that I need to clean before passing to executemany?

Answer

Andy picture Andy · Mar 3, 2014

The problem was the data going into the tags column. It was attempting to pass a list instead of a string.

For the sample in my original question, I used this code to convert it to a string.

','.join([u'plotting', u'equation-solving', u'differential-equations', u'numerical-integration', u'notebooks'])

It should also be noted that I messed up my commit line. It should be db.commit() not cur.commit()