-----------------------------------------------------------
-- |
-- Module      :  HaskellDB
-- Copyright   :  Daan Leijen (c) 1999, daan@cs.uu.nl
--                HWT Group (c) 2003, haskelldb-users@lists.sourceforge.net
-- License     :  BSD-style
-- 
-- Maintainer  :  haskelldb-users@lists.sourceforge.net
-- Stability   :  experimental
-- Portability :  non portable
--
-- HaskellDB is a Haskell library for expressing database queries and
-- operations in a type safe and declarative way. HaskellDB compiles a
-- relational algebra-like syntax into SQL, submits the operations to the
-- database for processing, and returns the results as ordinary Haskell
-- values.
--
-- This is the main module that the user should 
-- import. Beside this module, the user should import a
-- particular database binding (ie. "Database.HaskellDB.HSQL.ODBC") 
-- and database definitions.
--
-- HaskellDB was originally written by Daan Leijen and it's 
-- design is described in the paper Domain Specific Embedded 
-- Compilers, Daan Leijen and Erik Meijer. 2nd USENIX 
-- Conference on Domain-Specific Languages (DSL), Austin, 
-- USA, October 1999 (<http://www.usenix.org/events/dsl99/>).
--
-- This new version of HaskellDB was produced as a student project at
-- Chalmers University of Technology in Gothenburg, Sweden. The aim of the
-- project was to make HaskellDB a practically useful database library.
-- That work is described in 
-- Student Paper: HaskellDB Improved, 
-- Björn Bringert, Anders Höckersten, Conny Andersson, Martin Andersson, 
-- Mary Bergman, Victor Blomqvist and Torbjörn Martin. 
-- In Proceedings of the ACM SIGPLAN 2004 Haskell Workshop, Snowbird, Utah, 
-- USA, September 22, 2004.
-- (<http://haskelldb.sourceforge.net/haskelldb.pdf>)
--
-----------------------------------------------------------
module Database.HaskellDB
	( Rel, Attr, Expr, Table, Query, OrderExpr

        -- * Records
	, HasField, Record, Select, ( # ), ( << ), (<<-), (!), (!.)
	
        -- * Relational operators
	, restrict, table, project
	, union, intersect, divide, minus

	-- * Query expressions
	, (.==.) , (.<>.), (.<.), (.<=.), (.>.), (.>=.)
	, (.&&.) , (.||.)
	, (.*.) , (./.), (.%.), (.+.), (.-.), (.++.)
	, _not, like, _in, cat, _length
	, isNull, notNull, fromNull
	, constant, constJust
	
	, count, _sum, _max, _min, avg
	, stddev, stddevP, variance, varianceP
	
	, asc, desc, order
	, top --, topPercent

        , _case
	, _default

	-- * Database operations
	, Database				-- abstract
	, query
	, insert, delete, update, insertQuery
	, tables, describe, transaction

	-- * Debugging
	, showQuery, showQueryUnOpt, showSql, showSqlUnOpt
	) where

import Database.HaskellDB.HDBRec
-- PrimQuery type is imported so that haddock can find it.
import Database.HaskellDB.PrimQuery (PrimQuery)
import Database.HaskellDB.Sql.Generate (sqlQuery)
import Database.HaskellDB.Sql.Default (defaultSqlGenerator)
import Database.HaskellDB.Sql.Print (ppSql)
import Database.HaskellDB.Optimize  (optimize)
import Database.HaskellDB.Query
import Database.HaskellDB.Database
import Text.PrettyPrint.HughesPJ (Doc)

-- | Shows the optimized SQL for the query.
instance Show (Query (Rel r)) where
  showsPrec _ query = shows (showSql query)

-- | Shows the optimized 'PrimQuery'.
showQuery :: Query (Rel r) -> String
showQuery = show . optimize . runQuery

-- | Shows the unoptimized 'PrimQuery'.
showQueryUnOpt :: Query (Rel r) -> String
showQueryUnOpt = show . runQuery

-- | Shows the optimized SQL query.
showSql :: Query (Rel r) -> String
showSql = show . ppSql . sqlQuery defaultSqlGenerator . optimize . runQuery 

-- | Shows the unoptimized SQL query.
showSqlUnOpt :: Query (Rel r) -> String
showSqlUnOpt = show . ppSql . sqlQuery defaultSqlGenerator . runQuery