Reputation: 71
I have a sqlite database with DATE columns which i am unable to match via my SQL in python. I read the documentation from https://docs.python.org/3/library/sqlite3.html#module-functions-and-constants and tried below:
import sqlite3
import datetime
con = sqlite3.connect(":memory:", detect_types=sqlite3.PARSE_DECLTYPES|sqlite3.PARSE_COLNAMES)
cur = con.cursor()
cur.execute("create table test(d date, ts timestamp)")
today = datetime.date.today()
now = datetime.datetime.now()
cur.execute("insert into test(d, ts) values (?, ?)", (today, now))
cur.execute('select current_date as "d [date]" from test') #No errors
cur.execute('select current_date as "d [date]" from test where current_date = ?', today ) #ValueError: parameters are of unsupported type
r = cur.fetchall()
print(r)
con.close()
Can someone explain why i get "ValueError: parameters are of unsupported type" on the second SQL statement?
Upvotes: 1
Views: 190
Reputation: 3541
If you read the documentation you'll see that execute
expects a tuple containing one element for every question mark in the statement.
If you change it to
cur.execute('select current_date as "d [date]" from test where current_date = ?', (today,) )
It will work. Note the ,
after the item, necessary to avoid it being "optimized" as a single element. Alternative you could use a list:
cur.execute('select current_date as "d [date]" from test where current_date = ?', [today] )
Upvotes: 1