I have a simple table (named test) as:
id | integer name | character varying(100) intval | integer
When I try to use prepare statement to update the name like this in python. (I am using python-pgsql http://pypi.python.org/pypi/python-pgsql/)
>>> for i in db.execute("select * from test"): print i ... (1, 'FOO', None) >>> query = "UPDATE test set name = '$1' where name = '$2'" >>> cu.execute(query, "myname", "FOO") Traceback (most recent call last): File "<input>", line 1, in <module> File "/usr/lib/python2.7/site-packages/pgsql.py", line 119, in execute ret = self._source.execute(operation, params) ProgrammingError: ERROR: could not determine data type of parameter $1
The demo file for the module can be seen at http://sprunge.us/VgLY?python.
I'm guessing that it could be your single quotes around
$2 inside your string. In the main changes from PYGresql it says that:
So I'm assuming the single quotes are overloading the string with too many quotes, or just breaking the parser in python-pgsql.
Dont add single quotes with $1 and $2 .... It might be leading to unrecognition of type...