+ --Keyword -> id -> ()
+ setCurrent :: a -> String -> String -> IO Bool
+
+ --Keyword -> Full text -> id
+ update :: a -> String -> String -> String -> String -> IO String
+
+data Markup = Text String
+ | Bold String
+ | Paragraph [Markup]
+
+type Document = [Markup]
+
+newtype PGB = PGB DBService
+
+createPGB :: String -> String -> String -> String -> IO PGB
+createPGB host database user password = let db = createDBService host database "" user password Nothing in return (PGB db)
+
+
+testDB = createPGB "wave" "wiki" "wiki" "12wiki34db"
+
+instance Backend PGB where
+
+ getCurrent (PGB db) key = do
+ result <- selectReturnTuples db $ "SELECT fulltext,timestamp FROM curtexts WHERE keyword="++tov key
+ case result of
+ [text,date]:_ -> return (Just (text,date))
+ _ -> return Nothing
+
+ getList (PGB db) key = do
+ list <- selectReturnTuples db $ "SELECT id, timestamp, author, comment from fulltexts WHERE keyword = "++tov key
+ return $ map (\[id,date,author,comment] -> (id,date,author,comment)) list
+
+ get (PGB db) key id = return ""
+
+ setCurrent (PGB db) key id = do
+ full <- selectReturnTuples db $ "SELECT keyword FROM fulltexts WHERE keyword="++tov key++" AND id='"++id++"'"
+ cur <- selectReturnTuples db $ "SELECT keyword FROM curtexts WHERE keyword="++tov key
+ case full of
+ [[]] -> do
+ return False
+ _ -> do
+ rows <- case cur of
+ [[]] -> do
+ execute db $ "INSERT INTO current (keyword, id) VALUES ("++tov key++","++tov id++")"
+ _ -> do
+ execute db $ "UPDATE current SET id = "++tov id++" WHERE keyword = "++tov key
+ if rows == 1 then return True
+ else return False
+
+ update (PGB db) key text author comment = do
+ rows <- execute db $ "INSERT INTO fulltexts (keyword,fulltext, author, comment) VALUES ("++tov key++","++tov text++","++tov author++","++tov comment++")"
+ if rows == 0 then return ""
+ else do
+ [[id]] <- selectReturnTuples db $ "SELECT currval('fulltexts_id_seq')"
+ setCurrent (PGB db) key id
+ return id
+
+
+tov :: String -> String
+tov s = '\'':escapeQuery s++"'"
+