Safe Haskell	Safe-Inferred

Language.SQL.SimpleSQL.Syntax

Contents

Scalar expressions
Query expressions
- From

Description

The AST for SQL queries.

Synopsis

Scalar expressions

data ScalarExpr Source

Represents a scalar expression.

Constructors

NumLit String	a numeric literal optional decimal point, e+- integral exponent, e.g 10 10. .1 10.1 1e5 12.34e-6
StringLit String	string literal, currently only basic strings between single quotes with a single quote escaped using ''
IntervalLit	text of interval literal, units of interval precision, e.g. interval 3 days (3)
Fields ilLiteral :: String literal text ilUnits :: String units ilPrecision :: Maybe Int precision
Iden Name	identifier without dots
Star	star, as in select , t., count(*)
App Name [ScalarExpr]	function application (anything that looks like c style function application syntactically)
AggregateApp	aggregate application, which adds distinct or all, and order by, to regular function application
Fields aggName :: Name aggregate function name aggDistinct :: Maybe Duplicates distinct aggArgs :: [ScalarExpr] args aggOrderBy :: [OrderField] order by
WindowApp	window application, which adds over (partition by a order by b) to regular function application. Explicit frames are not currently supported
Fields wnName :: Name window function name wnArgs :: [ScalarExpr] args wnPartition :: [ScalarExpr] partition by wnOrderBy :: [OrderField] order by wnFrame :: Maybe Frame frame clause
BinOp ScalarExpr Name ScalarExpr	Infix binary operators. This is used for symbol operators (a + b), keyword operators (a and b) and multiple keyword operators (a is similar to b)
PrefixOp Name ScalarExpr	Prefix unary operators. This is used for symbol operators, keyword operators and multiple keyword operators
PostfixOp Name ScalarExpr	Postfix unary operators. This is used for symbol operators, keyword operators and multiple keyword operators
SpecialOp Name [ScalarExpr]	Used for ternary, mixfix and other non orthodox operators, including the function looking calls which use keywords instead of commas to separate the arguments, e.g. substring(t from 1 to 5)
Case	case expression. both flavours supported
Fields caseTest :: Maybe ScalarExpr test value caseWhens :: [([ScalarExpr], ScalarExpr)] when branches caseElse :: Maybe ScalarExpr else value
Parens ScalarExpr
Cast ScalarExpr TypeName	cast(a as typename)
TypedLit TypeName String	prefix 'typed literal', e.g. int '42'
SubQueryExpr SubQueryExprType QueryExpr	exists, all, any, some subqueries
In Bool ScalarExpr InThing	in list literal and in subquery, if the bool is false it means not in was used ('a not in (1,2)')

Instances

Eq ScalarExpr
Read ScalarExpr
Show ScalarExpr

data Name Source

Represents an identifier name, which can be quoted or unquoted.

Constructors

Name String
QName String

Instances

Eq Name
Read Name
Show Name

data TypeName Source

Represents a type name, used in casts.

Constructors

TypeName String
PrecTypeName String Int
PrecScaleTypeName String Int Int

Instances

Eq TypeName
Read TypeName
Show TypeName

data Duplicates Source

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.

Constructors

Distinct
All

Instances

Eq Duplicates
Read Duplicates
Show Duplicates

data OrderField Source

Represents one field in an order by list.

Constructors

OrderField ScalarExpr Direction NullsOrder

Instances

Eq OrderField
Read OrderField
Show OrderField

data Direction Source

The direction for a column in order by.

Constructors

Asc
Desc

Instances

Eq Direction
Read Direction
Show Direction

data NullsOrder Source

Represents 'nulls first' or 'nulls last' in an order by clause.

Constructors

NullsOrderDefault
NullsFirst
NullsLast

Instances

Eq NullsOrder
Read NullsOrder
Show NullsOrder

data InThing Source

Used for 'expr in (scalar expression list)', and 'expr in (subquery)' syntax.

Constructors

InList [ScalarExpr]
InQueryExpr QueryExpr

Instances

Eq InThing
Read InThing
Show InThing

data SubQueryExprType Source

A subquery in a scalar expression.

Constructors

SqExists	exists (query expr)
SqSq	a scalar subquery
SqAll	all (query expr)
SqSome	some (query expr)
SqAny	any (query expr)

Instances

Eq SubQueryExprType
Read SubQueryExprType
Show SubQueryExprType

data Frame Source

Represents the frame clause of a window this can be [range | rows] frame_start or [range | rows] between frame_start and frame_end

Constructors

FrameFrom FrameRows FramePos
FrameBetween FrameRows FramePos FramePos

Instances

Eq Frame
Read Frame
Show Frame

data FrameRows Source

Represents whether a window frame clause is over rows or ranges.

Constructors

FrameRows
FrameRange

Instances

Eq FrameRows
Read FrameRows
Show FrameRows

data FramePos Source

represents the start or end of a frame

Constructors

UnboundedPreceding
Preceding ScalarExpr
Current
Following ScalarExpr
UnboundedFollowing

Instances

Eq FramePos
Read FramePos
Show FramePos

Query expressions

data QueryExpr Source

Represents a query expression, which can be:

a regular select;
a set operator (union, except, intersect);
a common table expression (with);
a values expression;
or the table syntax - 'table t', shorthand for 'select * from t'.

Constructors

Select
Fields qeDuplicates :: Duplicates qeSelectList :: [(Maybe Name, ScalarExpr)] the column aliases and the expressions qeFrom :: [TableRef] qeWhere :: Maybe ScalarExpr qeGroupBy :: [GroupingExpr] qeHaving :: Maybe ScalarExpr qeOrderBy :: [OrderField] qeOffset :: Maybe ScalarExpr qeFetch :: Maybe ScalarExpr
CombineQueryExpr
Fields qe0 :: QueryExpr qeCombOp :: CombineOp qeDuplicates :: Duplicates qeCorresponding :: Corresponding qe1 :: QueryExpr
With
Fields qeWithRecursive :: Bool qeViews :: [(Alias, QueryExpr)] qeQueryExpression :: QueryExpr
Values [[ScalarExpr]]
Table Name

Instances

Eq QueryExpr
Read QueryExpr
Show QueryExpr

makeSelect :: QueryExpr Source

Helper/'default' value for query exprs to make creating query expr values a little easier.

data CombineOp Source

Query expression set operators.

Constructors

Union
Except
Intersect

Instances

Eq CombineOp
Read CombineOp
Show CombineOp

data Corresponding Source

Corresponding, an option for the set operators.

Constructors

Corresponding
Respectively

Instances

Eq Corresponding
Read Corresponding
Show Corresponding

data Alias Source

Represents an alias for a table valued expression, used in with queries and in from alias, e.g. select a from t u, select a from t u(b), with a(c) as select 1, select * from a.

Constructors

Alias Name (Maybe [Name])

Instances

Eq Alias
Read Alias
Show Alias

data GroupingExpr Source

Represents an item in a group by clause.

Constructors

GroupingParens [GroupingExpr]
Cube [GroupingExpr]
Rollup [GroupingExpr]
GroupingSets [GroupingExpr]
SimpleGroup ScalarExpr

Instances

Eq GroupingExpr
Read GroupingExpr
Show GroupingExpr

From

data TableRef Source

Represents a entry in the csv of tables in the from clause.

Constructors

TRSimple Name	from t
TRJoin TableRef JoinType TableRef (Maybe JoinCondition)	from a join b
TRParens TableRef	from (a)
TRAlias TableRef Alias	from a as b(c,d)
TRQueryExpr QueryExpr	from (query expr)
TRFunction Name [ScalarExpr]	from function(args)
TRLateral TableRef	from lateral t

Instances

Eq TableRef
Read TableRef
Show TableRef

data JoinType Source

The type of a join.

Constructors

JInner
JLeft
JRight
JFull
JCross

Instances

Eq JoinType
Read JoinType
Show JoinType

data JoinCondition Source

The join condition.

Constructors

JoinOn ScalarExpr	on expr
JoinUsing [Name]	using (column list)
JoinNatural	natural join was used

Instances

Eq JoinCondition
Read JoinCondition
Show JoinCondition