Question

This my python code which is used to perform update operation from reading the csv file. I tried with this also. It doesn’t work out.

for i  in cin:
    try:
        conn=psycopg2.connect("dbname=pharmaflare user=postgres")
        cursor=conn.cursor()
        cursor.execute("UPDATE pharmaflare_drug_interaction SET se_interaction ='%s' WHERE primary_drug ='%s' AND secondary_drug ='%s' AND side_effect ='%s'"%(i[3],i[0],i[1],i[2]))
        conn.commit()
        cursor.close()
        conn.close()
        #print "done",i[0],i[1],i[2],i[3]
    except Exception as e:
        cerr.writerow(i)
        ferr.flush()
        traceback.print_exc(file=sys.stdout)
        continue

Here I am facing the exception like syntax error due to the QUOTE’s problem:
Wherever the single quotes presents this exception arises.

  Traceback (most recent call last):
  File "<ipython console>", line 5, in <module>
  ProgrammingError: syntax error at or near "S"
  LINE 1: ...secondary_drug ='NEUER' AND side_effect ='MENIERE'S DISEASE'

Is there any alternative way available to define query statement without troubling the Quotes problem?

Answer 1

There are a couple ways to solve it. The easy/hack way to do it is to employ the re.escape() function. That function can be thought of as an equivalent to PHP’s addslashes() function, though it pains me to make that comparison.

Having said that, my reading indicates psycopg2 takes advantage of PEP 249. If that’s true, then you should be able to pass in parameterized queries and have it escape them for you.