Represents a value expression. This is used for the expressions in select lists. It is also used for expressions in where, group by, having, order by and so on.

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

Represents a type name, used in casts.

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.

Represents one field in an order by list.

The direction for a column in order by.

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

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

A subquery in a value expression.

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

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

represents the start or end of a frame

Represents a query expression, which can be:

• a regular select;
• a set operator (union, except, intersect);
• a common table expression (with);
• a table value constructor (values (1,2),(3,4)); or
• an explicit table (table t).

Helper/'default' value for query exprs to make creating query expr values a little easier. It is defined like this:

makeSelect :: QueryExpr
makeSelect = Select {qeSetQuantifier = All
                    ,qeSelectList = []
                    ,qeFrom = []
                    ,qeWhere = Nothing
                    ,qeGroupBy = []
                    ,qeHaving = Nothing
                    ,qeOrderBy = []
                    ,qeOffset = Nothing
                    ,qeFetchFirst = Nothing}

Query expression set operators.

Corresponding, an option for the set operators.

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.

Represents an item in a group by clause.

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

The type of a join.

The join condition.