I'm trying to populate a database with a single column with a list of strings (links). I scraped the list and I must modify every single link before sending it to the database. This is the code:
for event in events:
link_url = "https://www.website.com"+event+"#all"
c.execute("INSERT INTO table (links) VALUES(?)", link_url)
I can get it working if I modify the variables and send a tuple, like this:
for event in events:
link_url = "https://www.website.com"+event+"#all"
link = (link_url,)
c.execute("INSERT INTO seriea (links) VALUES(?)", link_url)
but I don't want to use this solution since I want to get a list of strings back out later:
c = connection.execute('select links from table')
list_of_urls = c.fetchall()
But this gives me a list of tuples.
This is the error I have: ProgrammingError: Incorrect number of bindings supplied. The current statement uses 1, and there are 80 supplied.
I think that's because the string characters are counted (actually more but I noticed that the number before "supplied" changes with the link fed)
I don't want to use this solution since I want to get a list of strings back out later:
c = connection.execute('select links from table') list_of_urls = c.fetchall()
But this gives me a list of tuples.
The list of tuples you're getting when you do a select have nothing to do with the way you insert data. Remember, tables have two dimensions:
id | links | something | else |
---|---|---|---|
1 | "foo" | "bar" | "baz" |
2 | "quux" | "herp" | "derp" |
When you do a select you get a list that corresponds to the rows here. But each row has multiple fields: id
, links
, something
, and else
. Each tuple in the list contains the values for each of the fields in the table.
If you just want the URLs as a list of strings you can use a list comprehension or similar:
c = connection.execute('select links from table')
list_of_rows = c.fetchall()
list_of_strings = [row[0] for row in list_of_rows]
# ^ index of first element in
# ^^^ the tuple of values for each row
Note that you do have to provide a tuple or other sequence when you insert the data:
For the qmark style,
parameters
must be a sequence . For the named style, it can be either a sequence or dict instance. The length of the sequence must match the number of placeholders, or aProgrammingError
is raised. If a dict is given, it must contain keys for all named parameters.
You might be thinking of the tuple part of it the wrong way. You don't need to pass in a tuple of URLs, you need to pass in a tuple of parameters . You're not saying "the links column should contain this tuple" but rather "this tuple contains enough values to fill in the placeholders in this query".
I'd rewrite that like so:
for event in events:
link_url = "https://www.website.com"+event+"#all"
c.execute("INSERT INTO seriea (links) VALUES(?)", (link_url,))
This is so you can have multiple parameters, eg
c.execute(
"INSERT INTO seriea (links, some, other) VALUES(?, ?, ?)",
(link_url, foo, bar),
)
The current statement uses 1, and there are 80 supplied.
I think that's because the string characters are counted
Yes, that's most likely what's happening. c.execute()
expects to receive a sequence, and strings are a sequence of characters.
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