145 lines
5.5 KiB
Plaintext
145 lines
5.5 KiB
Plaintext
|
|
> -- | The AST for SQL queries
|
|
> module Language.SQL.SimpleSQL.Syntax
|
|
> (-- * Scalar expressions
|
|
> ScalarExpr(..)
|
|
> ,TypeName(..)
|
|
> ,Duplicates(..)
|
|
> ,Direction(..)
|
|
> ,InThing(..)
|
|
> ,SubQueryExprType(..)
|
|
> -- * Query expressions
|
|
> ,QueryExpr(..)
|
|
> ,makeSelect
|
|
> ,CombineOp(..)
|
|
> ,Corresponding(..)
|
|
> -- ** From
|
|
> ,TableRef(..)
|
|
> ,JoinType(..)
|
|
> ,JoinCondition(..)
|
|
> ) where
|
|
|
|
> -- | Represents a scalar expression
|
|
> data ScalarExpr = NumLit String
|
|
> | StringLit String
|
|
> | IntervalLit String -- text of interval
|
|
> String -- units of interval
|
|
> (Maybe Int) -- precision
|
|
> | Iden String
|
|
> | Iden2 String String
|
|
> | Star
|
|
> | Star2 String
|
|
> | App String [ScalarExpr]
|
|
> | AggregateApp String (Maybe Duplicates)
|
|
> [ScalarExpr]
|
|
> [(ScalarExpr,Direction)]
|
|
> | WindowApp String [ScalarExpr] [ScalarExpr] [(ScalarExpr,Direction)]
|
|
> -- the binop, prefixop and postfix op
|
|
> -- are used for symbol and keyword operators
|
|
> -- these are used even for the multiple keyword
|
|
> -- operators
|
|
> | BinOp ScalarExpr String ScalarExpr
|
|
> | PrefixOp String ScalarExpr
|
|
> | PostfixOp String ScalarExpr
|
|
> -- the special op is used for ternary, mixfix and other non orthodox operators
|
|
> | SpecialOp String [ScalarExpr]
|
|
> | Case (Maybe ScalarExpr) -- test value
|
|
> [(ScalarExpr,ScalarExpr)] -- when branches
|
|
> (Maybe ScalarExpr) -- else value
|
|
> | Parens ScalarExpr
|
|
> | Cast ScalarExpr TypeName
|
|
> | CastOp TypeName String
|
|
> | SubQueryExpr SubQueryExprType QueryExpr
|
|
> | In Bool -- true if in, false if not in
|
|
> ScalarExpr InThing
|
|
> deriving (Eq,Show)
|
|
|
|
> data TypeName = TypeName String deriving (Eq,Show)
|
|
|
|
|
|
> -- Represents 'expr in (scalar expression list)', and 'expr in
|
|
> -- (subquery)' syntax
|
|
> data InThing = InList [ScalarExpr]
|
|
> | InQueryExpr QueryExpr
|
|
> deriving (Eq,Show)
|
|
|
|
> -- | A subquery in a scalar expression
|
|
> data SubQueryExprType = SqExists | SqSq | SqAll | SqSome | SqAny
|
|
> deriving (Eq,Show)
|
|
|
|
> -- | Represents a query expression, which can be a select, a 'set
|
|
> -- operator' (union/except/intersect), a common table expression
|
|
> -- (with), a values expression (not yet supported) or the table
|
|
> -- syntax - 'table t', shorthand for 'select * from t' (not yet
|
|
> -- supported).
|
|
> data QueryExpr
|
|
> = Select
|
|
> {qeDuplicates :: Duplicates
|
|
> ,qeSelectList :: [(Maybe String,ScalarExpr)]
|
|
> ,qeFrom :: [TableRef]
|
|
> ,qeWhere :: Maybe ScalarExpr
|
|
> ,qeGroupBy :: [ScalarExpr]
|
|
> ,qeHaving :: Maybe ScalarExpr
|
|
> ,qeOrderBy :: [(ScalarExpr,Direction)]
|
|
> ,qeLimit :: Maybe ScalarExpr
|
|
> ,qeOffset :: Maybe ScalarExpr
|
|
> }
|
|
> | CombineQueryExpr
|
|
> {qe1 :: QueryExpr
|
|
> ,qeCombOp :: CombineOp
|
|
> ,qeDuplicates :: Duplicates
|
|
> ,qeCorresponding :: Corresponding
|
|
> ,qe2 :: QueryExpr
|
|
> }
|
|
> | With [(String,QueryExpr)] QueryExpr
|
|
> deriving (Eq,Show)
|
|
|
|
TODO: add queryexpr parens to deal with e.g.
|
|
(select 1 union select 2) union select 3
|
|
I'm not sure if this is valid syntax or not
|
|
|
|
|
|
> -- | represents the Distinct or All keywords, which can be used
|
|
> -- before a select list, in an aggregate/window function
|
|
> -- application, or in a query expression 'set operator'
|
|
> data Duplicates = Distinct | All deriving (Eq,Show)
|
|
|
|
> -- | The direction for a column in order by.
|
|
> data Direction = Asc | Desc deriving (Eq,Show)
|
|
> -- | Query expression 'set operators'
|
|
> data CombineOp = Union | Except | Intersect deriving (Eq,Show)
|
|
> -- | Corresponding, an option for the 'set operators'
|
|
> data Corresponding = Corresponding | Respectively deriving (Eq,Show)
|
|
|
|
> -- | helper/'default' value for query exprs to make creating query expr values a little easier
|
|
> makeSelect :: QueryExpr
|
|
> makeSelect = Select {qeDuplicates = All
|
|
> ,qeSelectList = []
|
|
> ,qeFrom = []
|
|
> ,qeWhere = Nothing
|
|
> ,qeGroupBy = []
|
|
> ,qeHaving = Nothing
|
|
> ,qeOrderBy = []
|
|
> ,qeLimit = Nothing
|
|
> ,qeOffset = Nothing}
|
|
|
|
> -- | Represents a entry in the csv of tables in the from clause.
|
|
> data TableRef = SimpleTableRef String -- from t
|
|
> | JoinTableRef TableRef JoinType TableRef (Maybe JoinCondition) -- from a join b
|
|
> | JoinParens TableRef -- from (a)
|
|
> | JoinAlias TableRef String (Maybe [String]) -- from a as b(c,d)
|
|
> | JoinQueryExpr QueryExpr -- from (query expr)
|
|
> deriving (Eq,Show)
|
|
|
|
TODO: add function table ref
|
|
|
|
> -- | The type of a join
|
|
> data JoinType = JInner | JLeft | JRight | JFull | JCross
|
|
> deriving (Eq,Show)
|
|
|
|
> -- | The join condition.
|
|
> data JoinCondition = JoinOn ScalarExpr -- ^ on expr
|
|
> | JoinUsing [String] -- ^ using (column list)
|
|
> | JoinNatural -- ^ natural join was specified
|
|
> deriving (Eq,Show)
|