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{-# LANGUAGE OverloadedStrings, QuasiQuotes #-}
module Y2017.M09.D20.Exercise where
import Control.Monad (void)
import Data.ByteString.Lazy.Char8 (ByteString)
import qualified Data.ByteString.Lazy.Char8 as BL
import Data.Map (Map)
import Database.PostgreSQL.Simple
import Database.PostgreSQL.Simple.SqlQQ
import Database.PostgreSQL.Simple.ToRow
import Database.PostgreSQL.Simple.ToField
import Network.HTTP.Conduit
-- below imports available via 1HaskellADay git repository
import Store.SQL.Connection (connectInfo)
This week we have been working on encoding and decoding strings to ints and
back, using a 'dictionary,' or mapping between to the two to facilitate these
Today we're going to take it up a notch.
import Y2017.M09.D14.Exercise
The above import was an exercise to store article text, and some metadata about
the articles in a PostgreSQL data store. Today, using these articles, we're
going to rip and to rend them apart into keywords...
import Y2017.M09.D15.Exercise
And then store these keywords into a dictionary AND a keyword-strength store...
Ooh! How exciting!
Okay, let's get to it.
The keyword table in the database is structured thus:
data Key = Key { keyId :: Int, keyword :: String }
deriving (Eq, Ord, Show)
-- Given an insert statement for a new keyword is:
insertKeyStmt :: Query
insertKeyStmt = [sql|INSERT INTO keyword (id, keyword) VALUES (?,?)|]
-- Question 1: what is its ToRow instance definition?
instance ToRow Key where
toRow kw = undefined
Today we're going to be tying together the results of Y2017.M09.D15.Exercise's
keyword extraction with the data store, so we also need a keywords-with-their-
strengths-per-article table, and this we call article_keyword in the database.
It is structured thus:
data ArticleKeyWord = AKW { artId, kwId :: Int, kw :: KeyWord }
deriving (Eq, Ord, Show)
-- given the insert statement for a keyword for an article is:
insertAKWStmt :: Query
insertAKWStmt = [sql|INSERT INTO article_keyword
(article_id, keyword_id, keyword_count, keyword_strength)
VALUES (?,?,?,?)|]
-- Question 2: what is ArticleKeyWord's ToRow instance definition?
instance ToRow ArticleKeyWord where
toRow akw = undefined
-- Question 3: the biggy
Let's say the results of the query
select id from article where article_id = 'AP900327-0094.txt';
against the data store returns the id = 45.
1. populate the keyword table with the dictionary resulting from
>>> wordcontext <- kea 0 Map.empty <$> BL.readFile testFile
insertAllKeys :: Connection -> Dictionary -> IO ()
insertAllKeys conn dict = undefined
-- the above function assumes an empty keyword table
-- hint: you may wish to convert the Dictionary value to [Key]
-- then 2. insert all the keywords for AP900327-0094.txt into article_keyword
insertAllArticleKeyWords :: Connection -> Int -> Map Int KeyWord -> IO ()
insertAllArticleKeyWords conn artId kws = undefined
-- hint: you may wish to convert kws to [ArticleKeyWord]
-- We'll look at reading from these tables tomorrow.