Squeal.PostgreSQL.Expression.Sort

sort expressions

Sort

data SortExpression grp lat with db params from where

SortExpressions are used by orderBy to optionally sort the results of a Query. Asc or Desc set the sort direction of a NotNull result column to ascending or descending. Ascending order puts smaller values first, where "smaller" is defined in terms of the .< operator. Similarly, descending order is determined with the .> operator. AscNullsFirst, AscNullsLast, DescNullsFirst and DescNullsLast options are used to determine whether nulls appear before or after non-null values in the sort ordering of a Null result column.

Constructors

Asc

Fields

• :: Expression grp lat with db params from ('NotNull ty)

  sort by

• -> SortExpression grp lat with db params from

Desc

Fields

• :: Expression grp lat with db params from ('NotNull ty)

  sort by

• -> SortExpression grp lat with db params from

AscNullsFirst

Fields

• :: Expression grp lat with db params from ('Null ty)

  sort by

• -> SortExpression grp lat with db params from

AscNullsLast

Fields

• :: Expression grp lat with db params from ('Null ty)

  sort by

• -> SortExpression grp lat with db params from

DescNullsFirst

Fields

• :: Expression grp lat with db params from ('Null ty)

  sort by

• -> SortExpression grp lat with db params from

DescNullsLast

Fields

• :: Expression grp lat with db params from ('Null ty)

  sort by

• -> SortExpression grp lat with db params from

Instances

RenderSQL [SortExpression grp lat with db params from]

Defined in Squeal.PostgreSQL.Expression.Sort

Methods

renderSQL :: [SortExpression grp lat with db params from] -> ByteString

Show (SortExpression grp lat with db params from)

Defined in Squeal.PostgreSQL.Expression.Sort

Methods

showsPrec :: Int -> SortExpression grp lat with db params from -> ShowS

show :: SortExpression grp lat with db params from -> String

showList :: [SortExpression grp lat with db params from] -> ShowS

RenderSQL (SortExpression grp lat with db params from)

Defined in Squeal.PostgreSQL.Expression.Sort

Methods

renderSQL :: SortExpression grp lat with db params from -> ByteString

class OrderBy expr grp | expr -> grp where

The orderBy clause causes the result rows of a TableExpression to be sorted according to the specified SortExpression(s). If two rows are equal according to the leftmost expression, they are compared according to the next expression and so on. If they are equal according to all specified expressions, they are returned in an implementation-dependent order.

You can also control the order in which rows are processed by window functions using orderBy within Over.

Methods

orderBy

Arguments

:: [SortExpression grp lat with db params from]

sorts

-> expr lat with db params from

-> expr lat with db params from

Instances

OrderBy (TableExpression grp) grp

Defined in Squeal.PostgreSQL.Query.Table

Methods

orderBy :: forall (lat :: FromType) (with :: FromType) (db :: SchemasType) (params :: [NullType]) (from :: FromType). [SortExpression grp lat with db params from] -> TableExpression grp lat with db params from -> TableExpression grp lat with db params from

OrderBy (AggregateArg xs) 'Ungrouped

Defined in Squeal.PostgreSQL.Expression.Aggregate

Methods

orderBy :: forall (lat :: FromType) (with :: FromType) (db :: SchemasType) (params :: [NullType]) (from :: FromType). [SortExpression 'Ungrouped lat with db params from] -> AggregateArg xs lat with db params from -> AggregateArg xs lat with db params from

OrderBy (WindowDefinition grp) grp

Defined in Squeal.PostgreSQL.Expression.Window

Methods

orderBy :: forall (lat :: FromType) (with :: FromType) (db :: SchemasType) (params :: [NullType]) (from :: FromType). [SortExpression grp lat with db params from] -> WindowDefinition grp lat with db params from -> WindowDefinition grp lat with db params from